One that greets, acclaims, or catches someone's attention.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "hailer" in a sentence
"Now I think it would take a heart of stone not to laugh at Gordon Brown ` s belated conversion to the union which we can see from the direction of the BBC ` s loud hailer is actually only designed to dissipate English nationalism."
"It had taken more than two hours of loud hailer persuasion, but the door was easing open."
"It can stand sentry at a checkpoint, and warn people away with a police-style hailer, a non-blinding laser, tear gas or smoke grenades."