Oxford Dictionaries has this example under ADJECTIVE 'lightning':

(1) Roman is lightning quick and improving every day in practice, and Bean showed playmaking ability in the preseason.

The adjective is categorized in the dictionary as [ATTRIBUTIVE], which the same dictionary defines as:

(Of an adjective or other modifier) preceding the word that it modifies and expressing an attribute, as old in the old dog (but not in the dog is old) and expiry in expiry date. Contrasted with predicative.

At first glance, this lightning in (1) does not seem to be used attributively. For starters, the quick clearly is not a noun modified by the lightning. Then, is it used predicatively somehow not following the dictionary's own categorization as [ATTRIBUTIVE]?

The only possible way to make that happen is as if the lightning were in coordination with the quick. But that's unlikely, because without the quick, it sounds funky:

(1a) Roman is lightning and improving every day in practice, and Bean showed playmaking ability in the preseason. (?)

Merriam-Webster Learner's Dictionary says that lightning in similar cases is an adverb:

— lightning adverb

— used in combination

(2) an athlete with lightning-quick reflexes

(3) making lightning-fast adjustments

This just sounds absurd.

And I'm thinking maybe it's just a noun. But I need some feedback on this. Any thoughts?

  • 2
    Clearly the POS is different in different cases, and many of them don't fit the Classical Eight. There's around a dozen more Parts of Speech that've been discovered since DE PARTIBUS ORATIONIS ARS MINOR* was set in stone (well, almost in stone; "participle" has slipped off the approved list, while "adjective" has snuck in the back way). _Lightning is a metaphor for extremely, in a context where speed is being compared. It's also a misspelling for lightening, i.e, 'becoming (more) light', in any sense of light. Commented Sep 12, 2014 at 19:59
  • 3
    He's fast. How fast is he? He's as fast as lightning. He's lightning fast. He's red. How red is he? He's as red as an apple. He's apple red.
    – SrJoven
    Commented Sep 12, 2014 at 21:07
  • 1
    It's not just big. It's elephant big!
    – bib
    Commented Sep 13, 2014 at 0:49

5 Answers 5


"lightning" is primarily a noun and you can use it in a formula such as "as quick as lightning" or shorter "quick as lightning". In this special case we have an even shorter formula "lightning quick", in which the noun was placed before the adjective quick. In German we have the same formulas:

schnell wie der Blitz - "quick/fast as the flash" (translation word for word)

blitzschnell - "lightningfast" (written as one word")

As to German it is easy to say something about the word class of blitzschnell. The whole is a compound adjective with a noun as combining form in the first part.

As to English you get a bit into a jam and I should say it is subject to individual interpretation. Furthermore, there are two ways of looking at this composition "lightning quick": You can ask what kind of word class is the first element and I should say it is a noun. As to the whole composition I think there will be divergent views. I should say the whole composition acts as a compound adjective with the first element still being a noun as combining form.

(Mari-Lou A will not forgive me that I have drawn attention to a German expression that is parallel to an expression in English. I have tried to abstain from mentioning German, but sometimes the comparative method can make things clearer.)

  • I forgive you, but don't make it into a habit :)
    – Mari-Lou A
    Commented Sep 13, 2014 at 4:15
  • Thanks, Mari-Lou A. - By the way Merriam-Webster Learner's Dictionary spells the compound adjective with a hyphen: lightning-quick.
    – rogermue
    Commented Sep 13, 2014 at 4:29
  • Ah, now I understand what you meant. You are right, it must be furthermore. Correction accepted, thanks again.
    – rogermue
    Commented Sep 13, 2014 at 5:24
  • Hyphen: Spelling either lightning-quick (wictionary, BrE) or without hyphen.
    – rogermue
    Commented Sep 13, 2014 at 5:41
  • I'd opt for the hyphen, it shows the relationship between two words together. He has lightning-quick reflexes but His reflexes were quick as lightning.
    – Mari-Lou A
    Commented Sep 13, 2014 at 5:50

I believe in this case that lightning is a sort of "metaphorical adjective," meaning "quick as lightning."

  • "I'm plumb tired" = I have tires like a plumb?
    – Mitch
    Commented Sep 12, 2014 at 21:23
  • @Mitch That's a stretch. Tired = tires? plumb = upright.
    – SrJoven
    Commented Sep 12, 2014 at 21:56
  • @Mitch SrJoven Yes, but it's a nice stretch! Commented Sep 16, 2014 at 19:02
  • Yes, plumb as in straight up. "I am straight up tired." As in justifiably or truly.
    – Elliot
    Commented Oct 1, 2017 at 17:13

Noun as adjective would tend to answer this question.

It's common in English to use a noun as an adjective, especially when categorizing other nouns. One uses documents, and document folders, and document folder cabinets and document folder cabinet storage facilities.

What is the use of lightning in the question? It's a noun used as an adjective.

  • 1
    Wait, that's ambiguous: 'noun modifier' could be a modifier of a noun. Also 'noun' there is itself a noun modifier.
    – Mitch
    Commented Sep 16, 2014 at 19:28
  • 1
    @Mitch, SrJoven, Yes, because it still retains most of the syntactic properties of being a noun. For example, we can try to modify the modifying noun itself, and we will need to use an adjective or other noun, not an adverb: animal enclosure becomes wild animal enclosure, not wildly animal enclosure, that kind of thing. Commented Sep 17, 2014 at 8:40
  • 1
    @SrJoven I don't believe you did either. My point's just that the noun animal is still a noun whether it's modifying cage or not. It hasn't become an adjective, even though it's modifying a Noun. We can see this because it takes adjectives not adverbs as modifiers and so forth. If it was an adjective, it would usually be modified by an adverb. If your saying that animal in animal cage isn't functioning as a subject, I'd agree. It's functioning as a modifier in a Noun Phrase. Commented Sep 17, 2014 at 13:47
  • 1
    @SrJoven Well kinda. It's just that using that term implies that only adjectives really function as modifiers of nouns and also implies that it's the main job of an adjective to modify a noun (whereas they're used as predicative complements and other complements of verbs etc etc). Setting that aside though, don't you really want to say that lightning is being used as an adverb? Because it's modifying an adjective and usually we use adverbs to modify adjectives? Commented Sep 17, 2014 at 13:56
  • 1
    I agree with you that it's not an adverb! I just find the it's an X used as a Y schema a bit odd (lots of people here use it), so I was wanting to prod it a bit to find out what's up with it and see what the rationale was behind it. :) Commented Sep 17, 2014 at 15:52

From Google's definition of adverb:

a word or phrase that modifies or qualifies an adjective, verb, or other adverb or a word group, expressing a relation of place, time, circumstance, manner, cause, degree, etc. (e.g., gently, quite, then, there ).

I would call lightning an adverb in this case, as it is modifying an adjective.

"Roman is quick."
"How quick?"
"Lightning quick."


As @SrJoven suggests in his comment, nouns can be used attributively. Most often they are used as adjectives modifying other nouns

  • car park
  • wedding ring
  • lemon pie

When a noun modifies an adjective, it serves as an adverb

  • apple red
  • lightening quick
  • diamond hard
  • 1
    Your examples seem to show Nouns used as Nouns modifying other Nouns and then Nouns serving as Nouns modifying Adjectives! Commented Sep 13, 2014 at 15:08
  • @Araucaria Nouns can modify nouns or adjectives (or even verb forms). When they are used as such they still nouns, but used adjectivally or adverbially (or attributively).
    – bib
    Commented Sep 15, 2014 at 13:09

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.