subprogram

NOUN
10 LETTERS · STARTS WITH S

subprogram is a valid 10-letter word worth 17 points in Scrabble and 22 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
S1U1B3P3R1O1G2R1A1M3
1 + 1 + 3 + 3 + 1 + 1 + 2 + 1 + 1 + 3 =17 PTS
DOUBLE WORD → 34TRIPLE WORD → 51
MEANING

What does subprogram mean?