coition vs coitus

coition and coitus both are nouns.

Word	Noun	Adjective	Verb	Adverb
coition	Yes	No	No	No
coitus	Yes	No	No	No

As nouns, coition and coitus are synonyms defined as:

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

coition (noun)	coitus (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