Yes, PUBLICITY is a Scrabble word!

Letter values in Scrabble US: P 3, U 1, B 3, L 1, I 1, C 3, I 1, T 1, Y 4.

Is it a valid word?

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

a message issued in behalf of some product or cause or idea or person or institution
the quality of being open to public view

Also: promotional material.