musculus pectoralis

NOUN
19 LETTERS · STARTS WITH M

musculus pectoralis is a valid 19-letter word worth 26 points in Scrabble and 35 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
M3U1S1C3U1L1U1S1P3E1C3T1O1R1A1L1I1S1
3 + 1 + 1 + 3 + 1 + 1 + 1 + 1 + 0 + 3 + 1 + 3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 =26 PTS
DOUBLE WORD → 52TRIPLE WORD → 78
MEANING

What does musculus pectoralis mean?