chance upon

VERB /tʃæns_ə'pɑn/
11 LETTERS · STARTS WITH C

chance upon is a valid 11-letter word worth 19 points in Scrabble and 24 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
C3H4A1N1C3E1U1P3O1N1
3 + 4 + 1 + 1 + 3 + 1 + 0 + 1 + 3 + 1 + 1 =19 PTS
DOUBLE WORD → 38TRIPLE WORD → 57
MEANING

What does chance upon mean?