2 definitions by ilikeherbutshehasboyfriend

The Yason is a species of human that spends an entire day learning to play the guitar and masturbating when a university assignment is due. The Yason is also a virgin. The Yason is a dumb species.

A day which consists of eating pesto pasta, watching youtube and playing fortnite. The intention is to be productive and work but realistically, it never happens. People who indulge in jason days are usually greek or have greek connections (i.e. a greek house mate)