Yes, PIRACY is a Scrabble word!

Letter values in Scrabble US: P 3, I 1, R 1, A 1, C 3, Y 4.

Is it a valid word?

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

hijacking on the high seas or in similar contexts; taking a ship or plane away from the control of those who are legally entitled to it
the act of plagiarizing; taking someone's words or ideas as if they were your own

Not playable in Scrabble US: PLAGIARIZATION, PLAGIARISATION.