english
1
general::
Phrase(s): piece of cake Fig. something easy to do. • No problem. When you know what you’re doing, it’s a piece of cake. • Glad to help. It was a piece of cake. • Rescuing frightened cats is my specialty. Piece of cake!
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Something easily accomplished, as in I had no trouble finding your house? a piece of cake. This expression originated in the Royal Air Force in the late 1930s for an easy mission, and the precise reference is as mysterious as that of the simile EASY AS PIE. Possibly it evokes the easy accomplishment of swallowing a slice of sweet dessert.
American Heritage Idioms