A Spell

1. A shift (of work); (rare) a set of workers responsible for a specific turn of labour. [from 16th c.]
2. (informal) A definite period (of work or other activity). [from 18th c.]
3. (colloquial) An indefinite period of time (usually with a qualifier); by extension, a relatively short distance. [from 18th c.]
4. A period of rest; time off. [from 19th c.]
5. (colloquial, US) A period of illness, or sudden interval of bad spirits, disease etc. [from 19th c.]
6. (cricket) An uninterrupted series of alternate overs bowled by a single bowler. [from 20th c.]