Green’s Dictionary of Slang

Mona Lisa n.

[rhy. sl.]

1. a freezer.

[UK]Wheeler & Broadhead Upper Class Rhy. Sl. 12: When Ma finds out that Willy’s raided the Mona Lisa, she’ll wipe that smile off his face.
[UK]R. Puxley Fresh Rabbit.

2. a pizza.

[UK]R. Puxley Fresh Rabbit.