loony bin

NOUN
9 LETTERS · 2 SYLLABLES · STARTS WITH L

loony bin is a valid 9-letter word worth 13 points in Scrabble and 16 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
L1O1O1N1Y4B3I1N1
1 + 1 + 1 + 1 + 4 + 0 + 3 + 1 + 1 =13 PTS
DOUBLE WORD → 26TRIPLE WORD → 39
MEANING

What does loony bin mean?