Is there a term of phrases where there are multiple ways to say the same meaning (that is, the phrases are synonymous), but on the surface, the structure of at least some of the phrase components have opposite meaning (that is, at least some components of each phrase are antonyms)?

For example, "fill in" and "fill out" mean the same thing (in the context of a form, e.g.). However, "in" and "out" are antonyms.

This is sort of the opposite of Auto-Antonyms. Whereas those are single words/phrases which have at least two meanings which are antonyms of each other, I'm looking for two phrases which are synonymous but are made up of pairwise antonyms.

  • 2
    A heteronym, definition 3 is a step in the right direction (different words with the same meaning but different etymology), but note that definition 1 (same spelling, different sound and meaning) is more common for that word. It allows, but doesn't precisely address, the antonym aspect you're asking about.
    – Lawrence
    Commented Apr 20, 2016 at 13:37
  • Have you looked into chiasmuses (or chiasmi)? An example would be something like: "I wonder if he is working hard or hardly working?" Commented Apr 27, 2016 at 2:49
  • Awesome! Aweful?
    – NVZ
    Commented Apr 27, 2016 at 20:38
  • @MichaelLai cool term. I think, however, that that is a different phenomenon - the meaning changes between the two halves of the chiasmus. Maybe that's not something inherent to chiasmuses? (sounds like both plurals are accepted?) Commented May 17, 2016 at 0:46
  • @Lawrence check out Max Williams's answer below. I think this takes hetronym and nicely nuances it for this situation. Commented Jun 2, 2016 at 19:08

2 Answers 2


You could call them paradoxical heteronyms perhaps? Heteronyms obviously because they mean the same, and paradoxical because they appear, logically, to be mutually exclusive.



I would consider "fill in" and "fill out" to be verbs in modern usages.

Along the lines of "kick the bucket" conveying an indivisible meaning.

If this doesn't answer your question, provide another example.


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.