poor speller vs speller

poor speller and speller both are nouns.

Word	Noun	Adjective	Verb	Adverb
poor speller	Yes	No	No	No
speller	Yes	No	No	No

As nouns, poor speller and speller are synonyms defined as:

Other synonyms of poor speller include good speller.

poor speller (noun)	speller (noun)
someone who spells words	an introductory textbook to teach spelling
	someone who spells words