bad cooking; bad food
Internet slang abbreviation of 飯がまずい. Used to describe someone's poor cooking skills or unappetizing food, often in a humorous or derogatory way online.
Her cooking is infamous for being bad.
sadness at others' happiness
Internet slang abbreviation of 他人の幸せで飯がまずい. Expresses the feeling that seeing other people's happiness ruins one's appetite, i.e., makes one feel bitter or envious. Often used jokingly.
See also: メシウマ
Today's lunch is so bad it makes me want to cry.
Seeing my friend's marriage announcement makes me feel bitter.
When people flaunt their happiness on social media, it really kills my appetite.
Abbreviation of 飯がまずい (meshi ga mazui, 'the food is bad'). Sense 2 is a further abbreviation of the phrase 他人の幸せで飯がまずい (tanin no shiawase de meshi ga mazui, 'the food tastes bad because of others' happiness').