(verb) Hating on someone because of them being "irrelevant," which was what the famous YouTuber "Ricegum" did in his prime days... such a shame that he's also irrelevant now.
An example of ricegumming:
Person 1: Do have a crush on Emily?
Person 2: Nah! Don’t even like girls!
Person 1: So, how is your love life anyway?
Person 2: Great! You know I swimming in mad puss right now!