staircase shell

15 LETTERS · STARTS WITH S

staircase shell is a valid 15-letter word worth 19 points in Scrabble and 21 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

S1T1A1I1R1C3A1S1E1S1H4E1L1L1

1 + 1 + 1 + 1 + 1 + 3 + 1 + 1 + 1 + 0 + 1 + 4 + 1 + 1 + 1 =19 PTS

DOUBLE WORD → 38TRIPLE WORD → 57

MEANING

What does staircase shell mean?