1) to no longer breathe, have a pulse, or being unable to continue to be alive
2) refering to something that is no longer cool or good. Or that has never been.
3) in trouble, started as an exaggeration but now is completely literal
4) electronic that no longer works
5) anything that no longer works or is broken
6) anything that you can't figure out how to use and you want to blame the thing
1) My dog is dead
2) I wish I hadn't gone, that was so dead.
3) When my girlfriend finds out I'm gonna be so dead.
4) My phone is dead.
5) Dude, my hand died
6) Dammit I hate my laptop it is totally dead!