plica vocalis

NOUN
13 LETTERS · STARTS WITH P

plica vocalis is a valid 13-letter word worth 21 points in Scrabble and 27 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
P3L1I1C3A1V4O1C3A1L1I1S1
3 + 1 + 1 + 3 + 1 + 0 + 4 + 1 + 3 + 1 + 1 + 1 + 1 =21 PTS
DOUBLE WORD → 42TRIPLE WORD → 63
MEANING

What does plica vocalis mean?