tranquillizer

NOUN /træŋkwɪ,laɪzər/
13 LETTERS · 4 SYLLABLES · STARTS WITH T

tranquillizer is a valid 13-letter word worth 31 points in Scrabble and 35 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
T1R1A1N1Q10U1I1L1L1I1Z10E1R1
1 + 1 + 1 + 1 + 10 + 1 + 1 + 1 + 1 + 1 + 10 + 1 + 1 =31 PTS
DOUBLE WORD → 62TRIPLE WORD → 93
MEANING

What does tranquillizer mean?