sticker

Noun

• a short knife with a pointed blade used for piercing or stabbing

• a particularly difficult or baffling question or problem

• an adhesive label

• a small sharp-pointed tip resembling a spike on a stem or leaf

Related words

• Synonyms: 
  dagger , poser , stumper , toughie , gummed label , paster , spine , thorn , prickle , pricker , spikelet