thorn vs annoyance

thorn and annoyance both are nouns.

Word	Noun	Adjective	Verb	Adverb
thorn	Yes	No	No	No
annoyance	Yes	No	No	No

As nouns, annoyance is a hypernym of thorn; that is, annoyance is a word with a broader meaning than thorn:

thorn: something that causes irritation and annoyance
annoyance: something or someone that causes trouble; a source of unhappiness

Other hypernyms of thorn include bother, botheration, infliction, nuisance, pain, pain in the ass, pain in the neck.

thorn (noun)	annoyance (noun)
something that causes irritation and annoyance	the act of troubling or annoying someone
a Germanic character of runic origin	something or someone that causes trouble; a source of unhappiness
a small sharp-pointed tip resembling a spike on a stem or leaf	anger produced by some annoying irritation
	an unpleasant person who is annoying or exasperating
	the psychological state of being irritated or annoyed