Plesionyms are synonymous words which have slight differences in meaning.

What are the examples of it? I found:

  • Fog v Mist
  • Fearless v Brave

When and why are they are used?

What are the aspects which differentiate plesionymic synonyms from cognitive synonyms?

  • 1
    And what are the "slight differences in meaning" that differentiate these "plesionyms"? I must say this is a new concept; who originated it? Oct 20, 2018 at 19:40
  • 1
    The word plesionym is not in the respected Oxford Dictionary. Oct 20, 2018 at 19:44
  • 2
    Don't all synonyms have a slightly different meaning? I wanted to ask a question about this. The thesaurus gives you synonyms, words that are like the word you looked up, but not the same. Yet a lot of people use "synonym" to mean EXACTLY the same, especially when they say "the two words aren't synonymous". I'm confused. Edit: That term sounds like a swimming dinosaur.
    – Zebrafish
    Oct 20, 2018 at 19:48
  • 1
    Even the same word can can have different meanings . . . Oct 20, 2018 at 20:42
  • 1
    There are no exact synonyms
    – Mitch
    Oct 20, 2018 at 23:05

3 Answers 3


Why would you choose one word over another, when the two might be synonyms?

The best explanation was provided by Isaac Asimov:

R. Daneel said, "I do not understand the distinction you are making, Partner Elijah. Since 'murder' and 'homicide' are both used to represent the violent ending of the life of a human being, the two words must be interchangeable. Where, then, is the distinction?"

"Of the two words, one screamed out will more effectively chill the blood of a human being than the other will, Daneel."

"Why is that?"

"Connotations and associations; the subtle effect, not of dictionary meaning, but of years of usage; the nature of the sentences and conditions and events in which one has experienced the use of one word as compared with that of the other."

"There is nothing of this in my programming," said Daneel [...].

(from "The Robots of Dawn")


When words have a similar but slightly different meaning, there will be contexts where one is more appropriate than another. In other contexts, the difference may not be relevant so either is acceptable.

In your examples: A brave person and a fearless person may both perform the same feats that others may be too fearful to perform. However, a fearless person would not be afraid to perform the feat whereas a brave person may perform the feat despite being afraid. From an outside observer's perspective, if the person did not appear to be afraid, then the observer might use brave or fearless to describe the person. If, however, it was clear that the person was afraid but did it anyway, then only brave would make sense.


It depends on the context.

In a nearly polar land with frequent precipitation there will be many words used for snow and they aren't all synonyms: they describe different types of snow which are relevant to the environment.

But in an equatorial land where it never snows, the words snow and sleet and hail might be considered to be synonyms.

Your Answer

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

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