From Wiktionary, the free dictionary
Back-formation from boomer.
-oomer
- (4chan, Internet slang) Used to form the names of Wojak characters, or, by extension, caricaturized personifications of a given trait/quality.
- game + -oomer → goomer (“video game addict”)
- cum + -oomer → coomer (“masturbation addict”)
- consume + -oomer → consoomer (“consumerist”)