sexual intercourse vs coitus

sexual intercourse and coitus both are nouns.

Word	Noun	Adjective	Verb	Adverb
sexual intercourse	Yes	No	No	No
coitus	Yes	No	No	No

As nouns, sexual intercourse and coitus are synonyms defined as:

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

sexual intercourse (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