'like fun' definitions:

Definition of 'like fun'

From: GCIDE

Fun \Fun\ (f[u^]n), n. [Perh. of Celtic origin; cf. Ir. & Gael. fonn pleasure.] Sport; merriment; frolicsome amusement. "Oddity, frolic, and fun." --Goldsmith. [1913 Webster]
To make fun of, to hold up to, or turn into, ridicule.
in fun, jokingly; not seriously; for amusement.
like fun, definitely not; -- used adverbially, mostly to contradict a prior assertion; A: "He says he won't do it again." -- B: "Like fun he won't.". [1913 Webster + PJC]