like mad vs like sin

like mad and like sin both are adverbs.

Word	Noun	Adjective	Verb	Adverb
like mad	No	No	No	Yes
like sin	No	No	No	Yes

As adverbs, like mad and like sin are synonyms defined as:

like mad and like sin: (informal) with great speed or effort or intensity; used for emphasis

Other synonyms of like mad include like crazy, like hell, like the devil, like thunder.

like mad (adverb)	like sin (adverb)
(informal) with great speed or effort or intensity; used for emphasis	(informal) with great speed or effort or intensity; used for emphasis