ambiguous expression

20 LETTERS · STARTS WITH A

ambiguous expression is a valid 20-letter word worth 33 points in Scrabble and 40 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
A1M3B3I1G2U1O1U1S1E1X8P3R1E1S1S1I1O1N1
1 + 3 + 3 + 1 + 2 + 1 + 1 + 1 + 1 + 0 + 1 + 8 + 3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 =33 PTS
DOUBLE WORD → 66TRIPLE WORD → 99
MEANING

What does ambiguous expression mean?

1