cubic measure

NOUN /kjubɪk_'mɛʒər/
13 LETTERS · 3 SYLLABLES · STARTS WITH C

cubic measure is a valid 13-letter word worth 20 points in Scrabble and 26 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
C3U1B3I1C3M3E1A1S1U1R1E1
3 + 1 + 3 + 1 + 3 + 0 + 3 + 1 + 1 + 1 + 1 + 1 + 1 =20 PTS
DOUBLE WORD → 40TRIPLE WORD → 60
MEANING

What does cubic measure mean?