(historical) A whistle to summon attendants.

(ornithology) A call made between birds in a flock or a pair in order to maintain contact with one another when foraging, flying, etc.

simple past tense and past participle of call roll

(idiomatic) To make a roll call; to take attendance.

Any bell used to get someone's attention

present participle of call roll

To pay a short visit.

plural of call site

(programming) The section of code from which another section is called.

(American football) To change the play at the line of scrimmage by yelling out a new one. / (US, idiomatic) To change plans at the last minute based on newly revealed information.