A person who or a device which calls, summons loudly, or hails.
1880, Thomas Hardy, Fellow Townsmen, ch. 1:"Hullo, Downe—is that you?" said the driver of the vehicle, a young man of pale and refined appearance. "Jump up here with me, and ride down to your door."The other turned a plump, cheery, rather self-indulgent face over his shoulder towards the hailer."O, good evening, Mr. Barnet—thanks," he said.
