Singai is a more sophisticated and funny way of saying single. The term is used in the gaming world (most often on games like fortnite and rules of survival) and is often used as an insult. People take playing without the squad very seriously, and Playing singai is a cardinal sin in some gaming communities.

sing-guy
“Bro, hop on this squad game of fortnite”

“I can’t right now, I’m playing singles”

“Ewwww, your playing singai
by Mike nigher January 21, 2018