inhalation anesthetic

NOUN
21 LETTERS · STARTS WITH I

inhalation anesthetic is a valid 21-letter word worth 28 points in Scrabble and 31 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
I1N1H4A1L1A1T1I1O1N1A1N1E1S1T1H4E1T1I1C3
1 + 1 + 4 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 0 + 1 + 1 + 1 + 1 + 1 + 4 + 1 + 1 + 1 + 3 =28 PTS
DOUBLE WORD → 56TRIPLE WORD → 84
MEANING

What does inhalation anesthetic mean?