block up

VERB
8 LETTERS · STARTS WITH B

block up is a valid 8-letter word worth 17 points in Scrabble and 22 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
B3L1O1C3K5U1P3
3 + 1 + 1 + 3 + 5 + 0 + 1 + 3 =17 PTS
DOUBLE WORD → 34TRIPLE WORD → 51
MEANING

What does block up mean?