speller vs writer

speller and writer both are nouns.

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

As nouns, writer is a hypernym of speller; that is, writer is a word with a broader meaning than speller:

speller (noun)	writer (noun)
an introductory textbook to teach spelling	writes (books or stories or articles or the like) professionally (for pay)
someone who spells words	a person who is able to write and has written something