Dead (8)
(Other definitions for departed that I've seen before include "Quit" , "Went - dead" , "completely breathless" , "Left -- late" , "Left, went away" .)
'dead' is the definition.
(I know that dead can be written as deceased)
This is the entire clue.
(Other definitions for deceased that I've seen before include "Passed away" , "Defunct" , "Late" , "Pushing up the daisies" , "Recently dead" .)
(Other definitions for end that I've seen before include "'Conclusion, finale (3)'" , "Fine" , "Extremity" , "Cesation, conclusion" , "Objective or conclusion" .)
'dead' is the definition.
(similar in meaning)
This is all the clue.
(Other definitions for extinct that I've seen before include "Having died out, like the dinosaur" , "No longer existing" , "(Creature) no longer about" , "Ended" , "No more vital" .)