Please become dead to the world
I believe the answer is:
asleep
'dead to the world' is the definition.
(I've seen this before)
'please become' is the wordplay.
'become' indicates an anagram.
'please' is an anagram of 'ASLEEP'.
(Other definitions for asleep that I've seen before include "Please be at rest (6)." , "like a kipper" , "Inattentive; numbed" , "Dormant; inattentive" , "(Of a limb) numb" .)