Yes, BUCKEYES is a Scrabble word!

Letter values in Scrabble US: B 3, U 1, C 3, K 5, E 1, Y 4, E 1, S 1.

Is it a valid word?

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

the inedible nutlike seed of the horse chestnut
tree having palmate leaves and large clusters of white to red flowers followed by brown shiny inedible seeds
a native or resident of Ohio

Also: horse chestnut, aesculus hippocastanum.

Not playable in Scrabble US: OHIOAN.