1. spell off - Noun
2. spell off - Verb
In a spelling bee, of two or more participants, to spell words one after the other until a champion is determined. Usually refers to a series of rounds of spelling in which no spellers are eliminated.
(broadly) To participate in a spelling bee.
spell off (plural spell offs)
Alternative spelling of spell-off
spell off (third-person singular simple present spells off, present participle spelling off, simple past and past participle spelled off)
(transitive) To relieve (a worker) temporarily by taking his or her place.
In a spelling bee, an instance when two or more spellers go through several rounds without any being disqualified.
(broadly) A spelling bee.
Source: en.wiktionary.orgspell-off