The word spell has several meanings:

1. A period of time, usually short. A cold spell means several days of unusually cold weather. A dry spell describes weeks without rain. You might have a spell of bad luck when several unfortunate things happen one after another. Baseball players talk about hitting hot spells when they get lots of hits in a row, or cold spells when they can't seem to connect with the ball.
2. To write or say the letters of a word in the correct order. When you spell “necessary,” you need to remember it has one C and two S's. In a spelling bee, students compete to spell increasingly difficult words out loud. Being able to spell well helps you write clearly so others can understand your ideas.
3. A magical formula or incantation. In fairy tales and fantasy stories, a wizard might cast a spell to transform a prince into a frog, or a good fairy might break an evil spell. When something seems magical or enchanting, people say it casts a spell: “The beautiful music cast a spell over the audience.”
4. To mean or signal something. Dark clouds spell rain. A team's third straight loss might spell trouble for their playoff hopes. When circumstances spell disaster, they point toward a bad outcome.