Green’s Dictionary of Slang

motherfucking A! excl.

[ext. of fucking A! excl.]

(orig. US) an excl. used to denote astonishment, dismay; acceptance, praise, recognition.

‘gomer43’ posting 22 Aug. at Board 🌐 Re: motherfucker has to be the best compound word ever. MotherFUCKING A, man.
at quizilla.com 🌐 There was a fucking review in fucking Melody Maker... ‘Sounds like someone’s been taking singing lessons’. Like, motherfucking A!