fee-faw-fum, n. — Green’s Dictionary of Slang

fee-faw-fum n.

[the favoured phrase of the Giant in the nursery tale of Jack the Giant-Killer]

nonsense, spec. bloodthirsty, threatening nonsense.

1811		Lex. Balatronicum.
1841		Cantab. Indep. Press 16 Jan. 3/1: Fee, Faw, Fum! [...] Poor Mr Pryme, what will you do, after the flourish of the Tory trumpet.
1848		Cork Examiner 12 Jan. 4/4: The fee-faw-fum work would give Heraclitus himself the toothache with laughter.
1858		Cantab. Indep. Press 18 Sept. 5/3: Fee, Faw, Fum. There are many people who clearly love a bugbear. They like to be frightened [...] and they are fond of frightening others.
1868		Leamington Spa Courier 12 Sept. 5/1: There's Hamilton from India come, [...] All he can say is 'fee faw fum' 'Gainst Church and Constitution.
1880		Sunderland Dly Echo 30Sept. 3/1: The Chester Ward Fee-Faw-Fum [...] has a rooted antipathy to arrow-root.
1885		Bulletin (Sydney) 7 Mar. 12/3: Parson Brown, he calls all these arguments lies. / Sez they’re nothin’ on airth but jest fee, faw, fum; / An’ that all this big talk of our destinies / Is half on it ignorance an’ t’other half rum.