Yes, CANNABISES is a Scrabble word!

Letter values in Scrabble US: C 3, A 1, N 1, N 1, A 1, B 3, I 1, S 1, E 1, S 1.

Is it a valid word?

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

any plant of the genus Cannabis; a coarse bushy annual with palmate leaves and clusters of small green flowers; yields tough fibers and narcotic drugs
the most commonly used illicit drug; considered a soft drug, it consists of the dried leaves of the hemp plant; smoked or chewed for euphoric effect