Dead drunk, texting endlessly about Charlie (7)
I believe the answer is:
extinct
'dead' is the definition.
('extinct' can be similar in meaning to 'dead')
'drunk texting endlessly about charlie' is the wordplay.
'drunk' is an anagram indicator.
'endlessly' means to remove the last letter.
'about' indicates putting letters inside.
'charlie' becomes 'c' (phonetic alphabet: alpha, bravo, charlie etc.).
'texting' with its final letter taken off is 'textin'.
'textin' with letters rearranged gives 'extint'.
'extint' going around 'c' is 'EXTINCT'.
(Other definitions for extinct that I've seen before include "No longer extant" , "gone for ever" , "Dead (as a dodo?)" , "No longer living, like dinosaur" , "Wiped out" .)