sexual intercourse vs copulation

sexual intercourse and copulation both are nouns.

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

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

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

Other synonyms of sexual intercourse include carnal knowledge, coition, coitus, intercourse, relation, sex act, sexual congress, sexual relation.

sexual intercourse (noun)	copulation (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