spelldown vs contest

spelldown and contest both are nouns.

Word	Noun	Adjective	Verb	Adverb
spelldown	Yes	No	No	No
contest	Yes	No	Yes	No

As nouns, contest is a hypernym of spelldown; that is, contest is a word with a broader meaning than spelldown:

spelldown: a contest in which you are eliminated if you fail to spell a word correctly
contest: an occasion on which a winner is selected from among two or more contestants

Other hypernyms of spelldown include competition.

spelldown (noun)	contest (noun)
a contest in which you are eliminated if you fail to spell a word correctly	a struggle between rivals
	an occasion on which a winner is selected from among two or more contestants

spelldown (verb)	contest (verb)
	to make the subject of dispute, contention, or litigation