acid-fastness

/æsɪd_'fæstnɪs/

13 LETTERS · 3 SYLLABLES · STARTS WITH A

acid-fastness is a valid 13-letter word worth 18 points in Scrabble and 20 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

A1C3I1D2-0F4A1S1T1N1E1S1S1

1 + 3 + 1 + 2 + 0 + 4 + 1 + 1 + 1 + 1 + 1 + 1 + 1 =18 PTS

DOUBLE WORD → 36TRIPLE WORD → 54

MEANING

What does acid-fastness mean?