What part of speech is the word speller?

"Speller" can be a few different parts of speech, depending on its use in a sentence:

* Noun: A person who spells words.

* Example: "The young speller won the competition."

* Adjective: Relating to spelling.

* Example: "They used a speller dictionary to check their work."

* Verb: To spell words. (Less common)

* Example: "Can you speller that word for me?"

So, the specific part of speech depends on the context.