C3H4E1C3K5E1R1
18 points
CHECKER is validvalid
to mark with squares [v CHECKERED, CHECKERING, CHECKERS]
to divide into or mark with squares, esp. of alternate colours [v -ED, -ING, -S]
to mark with squares [v CHECKERED, CHECKERING, CHECKERS]
to divide into or mark with squares, esp. of alternate colours [v -ED, -ING, -S]