Definitions by Gurren Lagann Squad

dere 

Short for deredere (デレデレ), the counterpart of tsuntsun (ツンツン). Usually, but not always in reference to anime or manga.

1. Exhausted.
2. Lovestruck.
3. When a person becomes spoony in front of his/her lover

Person 1: My friend used to hate playing MMOs, but recently they've been drawing him in again.
Person 2: He's so dere.

dere by Gurren Lagann Squad July 15, 2010