|'Ugly' Betty, played by the patently un-ugly America Ferrera|
Noun phrase. Plural belles laides (pronounced same). Early 20th century.
[French, from belle beautiful + laide ugly (feminine adjectives).]
An attractive though ugly woman.
Belle laide was just too interesting a word to skip and, as much as we'd like to think we're above this superficial thinking, we've all met someone that we thought was unattractive (even ugly) but, for whatever reason, they somehow were attractive or became so over time.