1. A work
shift.
2. A time to report.
3. To direct others.
4. A decision.
5. Nomenclature.
Most often used in conjunction with a modifier: half-hour call,
curtain call, casting call, focus call, set call, show call, rehearsal call, photo call, call time, call cues, call back.
See also the thread:
http://www.controlbooth.com/forums/q...4038-call.html.