sticker vs gummed label

sticker and gummed label both are nouns.

Word	Noun	Adjective	Verb	Adverb
sticker	Yes	No	No	No
gummed label	Yes	No	No	No

As nouns, sticker and gummed label are synonyms defined as:

Other synonyms of sticker include paster.

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