1. [adj]  (followed by `to') not showing human feeling or sensitivity; unresponsive; "passersby were dead to our plea for help"; "numb to the cries for mercy"
2. [adj]  (informal) very tired; "was all in at the end of the day"; "so beat I could flop down and go to sleep anywhere"; "bushed after all that exercise"; "I'm dead after that long trip"

DEAD(P) is a 7 letter word that starts with D.