This is a term derived from the fandom name of MewGulf, Wanjaai (which means sweetheart).
Basically, this word refers to a
bunch of crackheads that spends all their
time musing about MewGulf interactions and coming up with inventions such as the Suppaseat products .
Being Waanjaians is a full
time job, not only do you have to wait for twitter and instagram updates from morning till
night, you also have to be a writer (for fanfictions), video editor (fanmade vids), and even become product designers and engineers (please refer to the Suppaseat line of products)!