i-adjective
irresistibly attractive; heart-melting; crush-inducing
Slang adjective derived from メロメロ (madly in love). Used mainly by younger speakers to describe someone or something so charming or cute that it makes you swoon. Often applied to idols, characters, or attractive people.
See also: メロメロ
新しく出たアイドルグループのメンバー、みんなメロいよね。
The members of the new idol group are all so heart-melting, aren't they?
このキャラクターの笑顔がメロすぎて、毎日見てしまう。
This character's smile is too adorable; I end up looking at it every day.