revolve about

VERB
13 LETTERS · STARTS WITH R

revolve about is a valid 13-letter word worth 20 points in Scrabble and 25 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
R1E1V4O1L1V4E1A1B3O1U1T1
1 + 1 + 4 + 1 + 1 + 4 + 1 + 0 + 1 + 3 + 1 + 1 + 1 =20 PTS
DOUBLE WORD → 40TRIPLE WORD → 60
MEANING

What does revolve about mean?