Yes, CONGRESS is a Scrabble word!

Letter values in Scrabble US: C 3, O 1, N 1, G 2, R 1, E 1, S 1, S 1.

Is it a valid word?

CONGRESS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

the legislature of the United States government
a meeting of elected or appointed representatives
a national legislative assembly
the act of sexual procreation between a man and a woman; the man's penis is inserted into the woman's vagina and excited until orgasm and ejaculation occur

Also: united states congress, u.s. congress, us congress, sexual intercourse, sex act, sexual congress, sexual relation, carnal knowledge.