'Fee-faw-fum' definitions:

Definition of 'Fee-faw-fum'

From: GCIDE

Fee-faw-fum \Fee`-faw`-fum"\, n. A nonsensical exclamation attributed to giants and ogres; hence, any expression calculated to impose upon the timid and ignorant. "Impudent fee-faw-fums." --J. H. Newman. [1913 Webster]