genus beta

NOUN
10 LETTERS · STARTS WITH G

genus beta is a valid 10-letter word worth 12 points in Scrabble and 16 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
G2E1N1U1S1B3E1T1A1
2 + 1 + 1 + 1 + 1 + 0 + 3 + 1 + 1 + 1 =12 PTS
DOUBLE WORD → 24TRIPLE WORD → 36
MEANING

What does genus beta mean?