Longman Dictionary of Contemporary English
banana skin
noun
EXAMPLES FROM CORPUS
▪ A tug-o'-war ensued and suddenly the rope came - unzipping all those carefully placed runners like a thumb through a banana skin.
▪ Carrie kicked off her shoes and peeled her leotard down like a banana skin.
▪ The enamel has peeled off the taps like so much banana skin, revealing dull, patchy brass.
Wiktionary
banana skin
n. 1 The outer skin of a banana, which being slippery is potentially dangerous if left lying around on the ground. 2 (context UK English) A cause of difficulty, or potential embarrassment.
WordNet
banana skin
n. the skin of a banana (especially when it is stripped off and discarded); "he slipped on a banana skin and almost fell" [syn: banana peel]