There are some problems that are minor and do not affect the overall operation at hand enough to stop it. For example, a broken radio is not a significant enough problem for driving a car. However, an empty gas tank is, and it needs to be resolved before the car can go.

What is an adjective to describe such a major problem or issue? I think I've heard a "gating issue" on a project I was involved in before, but a Google search didn't turn up much.

e.g. This is a _____ issue, so it needs to be resolved before we can make any progress.

  • Unhandled or fatal exception?
    – NVZ
    Commented May 25, 2016 at 3:51

15 Answers 15


A term used in the software industry is showstopper:

showstopper: n.

A hardware or (especially) software bug that makes an implementation effectively unusable; one that absolutely has to be fixed before development can go on. Opposite in connotation from its original theatrical use, which refers to something stunningly good.

So you could say, "This is a showstopper, so it needs to be resolved before we can make any progress."

  • 7
    +1 for noting that the connotation is reversed from it's theatrical sense.
    – Hot Licks
    Commented May 14, 2016 at 12:15
  • 3
    Showstopper is used in more industries than just software.
    – Chenmunka
    Commented May 14, 2016 at 21:32
  • 2
    I'm not sure showstopper is quite right. That is more of a must have/must do feature/task for the final result to be valid rather than an issue that stops progress on other parts.
    – JamesRyan
    Commented May 15, 2016 at 11:28
  • 2
    @JamesRyan: In the software world, hitting a showstopper frequently means your best developers are pulled from their assigned tasks and thrown onto the showstopper until a solution is found (and possibly until the solution has been coded and is in QA). So it does effectively stop progress on other fronts.
    – TMN
    Commented May 16, 2016 at 12:53
  • +1 "Showstopper" is the most common term. And its theatrical use actually means that some subset of the combined performance was so good it yanked the audience out their immersion in the performance i.e. they become aware they've seen something out of the ordinary and they pay attention to that and not the narrative being presented. Often causes spontaneous clapping, yelling, whistling etc which prevent the original production from continuing. In my theater experience, I've heard a truly bad performance described as a "showstopper" using sarcastic tone.
    – TechZen
    Commented May 16, 2016 at 20:51

Drop the word "issue" and say "This is a roadblock." which means:

something that stops progress



This is a blocking issue:

the action or process of obstructing movement, progress, or activity, in particular.
via Google

  • 2
    An empty tank might be even be considered a deadlock: car can't go because tank is empty, but tank can't be filled because car won't go to gas station... — That word really is computer-specific, though. Commented May 14, 2016 at 13:46
  • 6
    The phrase "blocker" or "blocking issue" is used in many technical project-management-type situations, not just software projects. Commented May 14, 2016 at 20:36
  • In CS, blocking makes me think of blocking threads...
    – Pockets
    Commented May 15, 2016 at 22:53
  • Where does the quote come from?
    – Andrew Leach
    Commented May 16, 2016 at 6:17
  • @AndrewLeach Google. I wasn't quite sure how to quote it with a link. Commented May 16, 2016 at 6:18

We call these a Blocker

blocker: n.

A task or problem that halts progress on a project.

  • 4
    Where does the quote come from?
    – Andrew Leach
    Commented May 16, 2016 at 6:18

"This is a critical issue."

According to ODO

3.2 Having a decisive or crucial importance in the success, failure, or existence of something:

"temperature is a critical factor in successful fruit storage"
"getting banks lending again was critical to any recovery"
"time-critical tasks"

For example:

BSOD or Blue Screen of Death is a serious problem seen on computers running Windows OS.

How To Geek's article "Everything You Need To Know About the Blue Screen of Death" (emphasis mine)

BSODs appear when Microsoft Windows encounters a critical error it can’t recover from, requiring a reboot and possibly resulting in lost work.


A blue screen occurs when Windows encounters a “STOP Error.” This critical failure causes Windows to crash and stop working. The only thing Windows can do is stop the computer and restart it.

Another example in the field of project management.

A critical task is defined, by Dictionary of Construction, as

A task or activity that lies on the critical path of the schedule, which if delayed will delay the completion of the project.

synonyms crucial, vital, essential, all-important, paramount, pre-eminent, fundamental, key, pivotal, decisive, climacteric, momentous

  • Critical just means important. It doesn't indicate anything about the task's blocked state. Commented May 15, 2016 at 8:02
  • @MartinSmith In a slightly different context, it means what you said. But as per the definition 3.2 I've quoted, "critical" issues need to be resolved to allow progress.
    – NVZ
    Commented May 15, 2016 at 8:20
  • Being critical is orthogonal to being blocked. It is entirely possible to have a task which is of crucial importance and is not blocked and not impeding progress. Commented May 15, 2016 at 8:47
  • Though actually I agree that it fits in the OP's example sentence as there the fact that the issue is blocked is implied. Commented May 15, 2016 at 8:53
  • @MartinSmith see my updated answer.
    – NVZ
    Commented May 16, 2016 at 8:44


This is probably the most professional term fitting your definition.

According to Google, it means:

a hindrance or obstruction in doing something.

Remember, however, to use it as a noun:

The empty gas tank was an impediment.

And not an adjective:

The empty gas tank was an impediment issue.

  • 2
    An impediment doesn't necessarily mean that progress has come to a complete halt though. A closed road necessitating a detour or a low gas tank could be impediments that require going out of your way, but they aren't blocking issues to a road trip in the same way that an engine fire would be. Commented May 15, 2016 at 2:22
  • It might be the most formal, but I don't think it is the most professional.
    – mattdm
    Commented May 17, 2016 at 10:26

A mechanical term might be something like a wrench in the wheels/gears. Used to mean a small item that can cause the entire machine to grind to a halt. It can of course be used metaphorically to relate to software or other showstopping problems as well.

  • "Spanner in the works"
    – mccainz
    Commented May 16, 2016 at 13:19
  • @mccainz - That works too, though it's more of a British variant. Many Americans wouldn't know what a "spanner" is. Not sure about Canada, Australia, etc. Commented May 16, 2016 at 13:30
  • And, of course, this is related to the origin of the word "sabotage", meaning throwing a shoe ("sabot") into the works of some machine.
    – Hot Licks
    Commented May 22, 2016 at 13:43
  • @HotLicks - True, but "sabotage" implies a deliberate action to muck things up, whereas a "wrench in the gears" could be accidental. Commented May 22, 2016 at 14:05
  • @DarrelHoffman - Could be, but generally isn't. (Note that there's the reasonably common idiom "threw a wrench/spanner in the works", but I've never heard "dropped a wrench/spanner in/into the works".)
    – Hot Licks
    Commented May 22, 2016 at 14:10

Try prohibitive (source - dictionary.com)

serving or tending to prohibit or forbid something.

sufficing to prevent the use, purchase, etc., of something

Also, restrictive (source - cambridge dictionary)

limiting the freedom of someone or preventing something from growing.


Try fatal.
In computing: "In computing, a fatal error or fatal exception error is an error that causes a program to abort..." -Wikipedia

[Middle English, fateful, from Old French, from Latin fātālis, from fātumprophecy, doom; see fate.]

Synonyms: fatal, deadly, lethal, mortal
These adjectives apply to what causes or is likely to cause death. Fatal describes conditions, circumstances, or events that have already caused death or are virtually certain to do so in the future: a fatal accident; a fatal illness.

Source: TheFreeDictionary

  • +1, that's the one I was scanning the page for. It should be pretty clear to any whether they've heard this usage or not. You don't recover from things that are fatal.
    – DCShannon
    Commented May 16, 2016 at 17:58

If your example is metaphorical, consider deal-breaker.

any issue or factor that is significant enough to terminate a negotiation, esp. in business or politics


"We've hit a wall," is fairly common, usually when breaking the news to someone. It connotes a solid object that is high and wide and cannot be easily worked around or climbed over.

The "go" and "no-go" is used by some software teams. Modeled on the NASA launch sequence, wherein each station reports whether the systems it monitors are "go" for launch of "no-go" for launch. A single "no-go" in an arbitrary long sequence of checks halts the launch.


Adding the British English corollary to Darrel Hoffman's answer.

Spanner in the works -to do something that prevents a plan or activity from succeeding


Try "impassable" issue.

The definition, from Merriam-Webster, is "impossible to pass, cross, or travel over".


There is really no commonly used adjective that meets your criteria. You could say "running out of gas is a showstopper", but if you had a list of "issues", you would more likely list that as "sufficient gas" or similar. if you then wanted to tag your issues you could use "non-negotiable", "required", "essential", etc. for those issues that would halt progress of not properly addressed.


One of the senses of bottleneck can be used in this context:

A hindrance to progress or production. - thefreedictionary.com

  • 7
    Bottlenecks actually allow work to progress, albeit rather slowly :)
    – NVZ
    Commented May 14, 2016 at 18:28
  • Yeah, my first thought was speed bump, but I didn't think that addressed the question adequately.
    – TMN
    Commented May 16, 2016 at 12:50

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.