surprise attack

NOUN /sər'praɪz_ə'tæk/
15 LETTERS · STARTS WITH S

surprise attack is a valid 15-letter word worth 22 points in Scrabble and 25 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
S1U1R1P3R1I1S1E1A1T1T1A1C3K5
1 + 1 + 1 + 3 + 1 + 1 + 1 + 1 + 0 + 1 + 1 + 1 + 1 + 3 + 5 =22 PTS
DOUBLE WORD → 44TRIPLE WORD → 66
MEANING

What does surprise attack mean?