Yes, SMEARING is a Scrabble word!

Letter values in Scrabble US: S 1, M 3, E 1, A 1, R 1, I 1, N 1, G 2.

Is it a valid word?

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

stain by smearing or daubing with a dirty substance
make a smudge on; soil by smudging
cover (a surface) by smearing (a substance) over it
charge falsely or with malicious intent; attack the good name and reputation of someone