First of lives finished off — dead (4)
I believe the answer is:
late
'dead' is the definition.
(similar in meaning)
'first of lives finished off' is the wordplay.
'first of lives' becomes 'l' (ast letter of 'lives').
'finished off' becomes 'ate' (finished eating).
'l'+'ate'='LATE'
(Other definitions for late that I've seen before include "Dead or not punctual" , "Former; behind time" , "Behindhand" , "Former, delayed" , "Dead or dilatory" .)