a sweet-smelling liquid ester, C 7 H 14 O 2 , a mixture of isomers derived from amyl alcohol and having the characteristic odor of bananas: used chiefly as a paint solvent and in artificial fruit flavors; amyl acetate.
Nonsense, esp when used to flatter and mislead; bunk
[1910+; perhaps fr the oily smoothness and fruity odor of banana oil, amyl acetate]
The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source
Idioms and Phrases with banana oil
Nonsense, exaggerated flattery, as in I should be on television? Cut out the banana oil! The precise analogy in this idiom is not clear, unless it is to the fact that banana oil, a paint solvent and artificial flavoring agent, has no relation to the fruit other than that it smells like it. Possibly it is a variation onsnake oil, a term for quack medicine that was extended to mean nonsense.