An individual, usually an ignorant blowhard, who sees it fit to trivialize the success of others despite never accomplishing anything themselves.
Steve: Did you hear? Mike got hired at that Fortune Five Hundred accounting firm on Wall Street.
Tom: Yeah, Whatever. Mike isn't even smart, just has a horseshoe up his ass, I could do that shit any day. Besides imma make millions anyways.
Steve: Dude, seriously? You're 30, trying to become a rapper, unemployed and living with your mom. serial-trivializer much?
Someone who likes to pass off the accomplishments/goals of others as overly simple or easily attainable despite being an unintelligent blowhard.
Steve: Did you hear? Nick got a job at that Fortune Five Hundred accounting firm.
John: Pfft, whatever. Nick ain't even smart, just got lucky. Besides, I could do that shit any day.
Steve: Dude, are you serious? You can't even spell 'because', you're living with your mom and trying to become a rapper. Bro you're a serial trivializer.