Fluids can flow into something (a chamber, pipeline, manifold, etc.) through an opening called an inlet, and out of it through an opening called an outlet. However, in some cases, the flow could be reversed, such that opening that previously served as an inlet now serves as an outlet, and vice versa.

Is there a word (or few-word phrase) that can be used to describe such an opening (which might serve as an inlet, an outlet, or both), but that could not also be used to describe something other than such an opening?

Example sentence: Gas flows into and out of the chamber through its [word needed].

Words like opening and aperture could also be applied to many things which do not serve as an inlet and/or outlet. Words like channel and pipeline could similarly be applied to other things, but also are not hypernyms of inlet and outlet (since an inlet/outlet could be a simple opening, rather than a channel). Port has an analogous meaning in computer networking and electrical circuits, but seems to be specific to those fields (such that 'fluid port' would not carry the desired meaning). Thesaurus & dictionary searches for these words (and for inlet and outlet themselves) did not yield any other suitable candidates.

A similar question (Is there a word or phrase that combines the meanings of 'inlet' and 'outlet'?) is scoped to a social network context, and the answers provided there do not seem applicable to this fluid flow context.

  • Just because words like channel, pipeline, pipe, duct, conduit, tube,... have other meanings doesn't seem like a very good reason for rejecting them all. Practically all English words have many meanings, but almost certainly if you use any of the possibilities I just listed, the context would make it obvious what you meant. Feb 20, 2021 at 18:21
  • @FumbleFingers words with multiple distinct meanings are perfectly fine, since the context can disambiguate between them (for example, if 'port' were an acceptable word here, the context would make it clear that it was not used to indicate a shipping facility). However, when the word has a single meaning that is far more general than desired, that can be problematic, as the desired meaning (something at which fluid flows in and/or out) is not adequately communicated. Feb 20, 2021 at 18:32
  • I'm afraid that so far as I'm concerned, if there was a suitable "hypernym" for your exact context (other than the "general purpose" terms already listed), it would almost certainly be Off Topic domain-specific terminology. But good luck with the search, anyway! :) Feb 20, 2021 at 18:40
  • 'Gate' is a useful hypernym, but is very polysemous. Feb 20, 2021 at 18:52
  • 1
    I would likely choose "port", when referring to an electrical gizmo.
    – Hot Licks
    Feb 20, 2021 at 20:01

1 Answer 1


A deleted post refers to port. I am familiar with this term in fluid engineering and there is some justification for it in:

ISO/TC131 developed a standard for port identification. ISO 11727 was developed to meet a global need. This standard identifies and provides definitions for proper numerical marking of ports on pneumatic directional control valves. These ports are supply and exhaust flow connections, actuator control connections, and pilot supply connections.

Fluid Power Journal

As used here it implies bi-directionality as you specify but it does not apply exclusively to the fluid connections, so to fit your specification would have to be constrained as the hypernymic noun phrase flow ports.

  • Thanks, glad to know that port can work after all. I think 'fluid port' might be preferable to 'flow port', but this is certainly very helpful! Feb 21, 2021 at 20:39

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.