problem vs sticker

problem and sticker both are nouns.

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

As nouns, sticker is a hyponym of problem; that is, sticker is a word with a more specific, narrower meaning than problem:

problem (noun)	sticker (noun)
a source of difficulty	a short knife with a pointed blade used for piercing or stabbing
a question raised for consideration or solution	an adhesive label
a state of difficulty that needs to be resolved	a particularly difficult or baffling question or problem
	a small sharp-pointed tip resembling a spike on a stem or leaf