Spell

a psychological state induced by (or as if induced by) a magical incantation

a time period for working (after which you will be relieved by someone else)

a period of indeterminate length (usually short) marked by some action or condition

a verbal formula believed to have magical force

orally recite the letters of or give the spelling of

indicate or signify

write or name the letters that comprise the conventionally accepted form of (a word or part of a word)

relieve (someone) from work by taking a turn

place under a spell

take turns working