From Middle English spell, spel, from Old English spell, from Proto-Germanic *spellą, from Proto-Indo-European *spel-. Cognate with dialectal German Spill, Icelandic spjall, spjalla, guðspjall and Albanian fjalë.
From Middle English spellen, from Anglo-Norman espeler, espeleir, Old French espeller, espeler (compare Modern French épeler), from Frankish *spelōn, merged with native Old English spellian, both eventually from Proto-Germanic *spellōną ("to speak"). Related with etymology 1. The sense “indicate a future event” probably in part a backformation from forespell.
From Middle English spelen, from Old English spelian, akin to Middle English spale, Old English spala.