It means OLD... It's a generation that's called the " Baby Boomers" but in slang if you say boomer it means old. So basically if you call someone/something a boomer then you are calling them old or calling the thing old.
by the dictonary BITCH November 13, 2019

An act in which a person grabs the sides of a metal folding chair tightly, pulling the ass as close to the seat as possible, and then farts as forcefully as possible.
The boomer reverberates loudly in all directions and resonates through the chair.
The boomer reverberates loudly in all directions and resonates through the chair.
Tom: "Holy crap! Did you hear that?"
John: "Yeah, what was that, a gunshot?"
Tom: "Naw, Vinnie just did a boomer!"
John: "Yeah, what was that, a gunshot?"
Tom: "Naw, Vinnie just did a boomer!"
by ctenah April 5, 2009

Yeah, Im a boomer
by Daddy 2 Shoes July 17, 2019

Boomer is a word used in every situation regardless whether it fits its definition or the context of the sentence
by AkinsoftIsUnfunnyChangeMyMind December 4, 2019

by I love Post Malone! March 26, 2020

another word for a male kangaroo according to fact # 185 on snapple...or a nick name for a certain guy....
jack: "goood morning mates! today we are going to be looking at boomers...and you will see one if you look outside the window on your right...."
by like im going to tell you September 10, 2005

Boomer is anyone who's older than you and is either complaining about younger generation, saying he hates his wife, or just believes in outdated beliefs about any subject. It can also be someone who doesn't know modern slang very well, or uses it in a "non-cool" way (not in a way that zoomer would use it)
by BigPPbarni June 18, 2020
