whacker
/ˈwakə/(also wacker)
noun
1A person or thing that strikes something forcefully.It's more fun to ski from your bumper than hike a rocky trail in the dark, wondering when you'll finally get those branch whackers off your back and on to your feet....
- That at least is the word from the ‘Nuevo Dia Newspaper’ which as all good Pinata whackers know means New Day.
- Four inches of surface and a finger-grooved linen Micarta grip make this one upscale whacker.
2Australian informal A person who is stupid or annoying (used as a general term of abuse): don’t humour this guy, he’s a whacker...
- I can't imagine how they dared break the rules, with all those regulatory whackers waiting to pounce.
- He was ordered to withdraw a description of an opponent as a "whacker".
- It would ease his mind if all those whackers were dead.
Origin
Early 19th century (in sense 'a heavy blow'): from whack + -er1. Sense 2 is a back formation from wacky.