coition vs sexual relation

coition and sexual relation both are nouns.

Word	Noun	Adjective	Verb	Adverb
coition	Yes	No	No	No
sexual relation	Yes	No	No	No

As nouns, coition and sexual relation are synonyms defined as:

coition and sexual relation: sexual activity between individuals, especially the insertion of a man's penis into a woman's vagina until orgasm and ejaculation occur

coition (noun)	sexual relation (noun)
sexual activity between individuals, especially the insertion of a man's penis into a woman's vagina until orgasm and ejaculation occur	sexual activity between individuals, especially the insertion of a man's penis into a woman's vagina until orgasm and ejaculation occur