chirk up

VERB
8 LETTERS · STARTS WITH C

chirk up is a valid 8-letter word worth 18 points in Scrabble and 20 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
C3H4I1R1K5U1P3
3 + 4 + 1 + 1 + 5 + 0 + 1 + 3 =18 PTS
DOUBLE WORD → 36TRIPLE WORD → 54
MEANING

What does chirk up mean?