speller

Etymology

From spell + -er.

noun

1. A person who spells.
   I'm a slow reader but a good speller.
   Without insisting on a difference between the inventors and the spellers of words, Socrates makes short work of this case. 2005, Michael W. Riley, Plato's Cratylus: Argument, Form, and Structure, page 124
2. A participant in a spelling bee.
3. (US) A book used to learn how to spell properly.
4. (computing) A spell checker.
   But Word's spelling program still isn't fully integrated into the word processor. For one thing, any changes and corrections you make from the speller's menus don't appear on-screen until you get back to your original file. 1987, PC Mag, volume 6, number 17, page 358