toughie vs sticker

toughie and sticker both are nouns.

Word	Noun	Adjective	Verb	Adverb
toughie	Yes	No	No	No
sticker	Yes	No	No	No

As nouns, toughie and sticker are synonyms defined as:

toughie and sticker: a particularly difficult or baffling question or problem

Other synonyms of toughie include poser, stumper.

toughie (noun)	sticker (noun)
a particularly difficult or baffling question or problem	a short knife with a pointed blade used for piercing or stabbing
an aggressive and violent young criminal	an adhesive label
	a particularly difficult or baffling question or problem
	a small sharp-pointed tip resembling a spike on a stem or leaf