light upon

VERB /laɪt_ə'pɑn/
10 LETTERS · STARTS WITH L

light upon is a valid 10-letter word worth 15 points in Scrabble and 19 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
L1I1G2H4T1U1P3O1N1
1 + 1 + 2 + 4 + 1 + 0 + 1 + 3 + 1 + 1 =15 PTS
DOUBLE WORD → 30TRIPLE WORD → 45
MEANING

What does light upon mean?