3 Answers

Part of Speech: noun
Definition: interval, period
Synonyms: bit, bout, course, go, hitch, interlude, intermission, patch, relay, season, shift, space, stint, streak, stretch, term, time, tour, tour of duty, trick, turn, while

I'm lost, what exactly do you want?  Also in what context is the word spell? Spell as in spell a word or spell as in cast a spell or spell as in an amount of time, "he sat down and rested a spell"? 

Are you looking for a same word or an opposite word? 

spell 2
(spl)n.1. a. A word or formula believed to have magic power.

b. A bewitched state; a trance.

2. A compelling attraction; charm or fascination: the spell of the theater.

tr.v. spelled, spell·ing, spellsTo put (someone) under a spell; bewitch.

[Middle English, discourse, from Old English.]