noun
eating lunch alone in a toilet stall
Slang referring to the practice of eating lunch in a toilet cubicle to avoid being seen eating alone, often associated with social anxiety or workplace/school isolation.
彼は友達がいなくて、便所飯をしているらしい。
He doesn't have any friends, so apparently he eats lunch in the toilet stall.
Informal word for 'meal' or 'cooked rice'; used here in a compound.
Compound of 便所 (toilet) and 飯 (meal). The exact origin is uncertain, but it emerged as internet slang describing the social phenomenon of eating alone in a toilet stall.