An insulting term used against someone, particularly a heavier set individual, who is being unreasonable, condescending, ignorant, or just a straight up Bitch. Being labeled a Beluga Susan is the equivalent of being called a "Fat Cunt" but in a more proper, discreet manner. This word is commonly used in work places, where an employee wants to call a fellow colleague a "Fat Bitch" but without getting in trouble.
"Samantha has been a real Beluga Susan today"

"Did you hear what Karen said about Daniel last night? Shes such a fucking Beluga Susan, it's unreal"

"Why do you gotta be a Beluga Susan"

"Nobody likes a Beluga Susan, I hope you know that"
by Dick Changler September 7, 2016
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