Live in apparent concealment! (3)
I believe the answer is:
are
'live' is the definition.
(both can mean exist)
'in apparent concealment' is the wordplay.
'in' says the answer is hidden in the clue.
'ARE' is hidden in the letters of 'apparent concealment'.
(Other definitions for are that I've seen before include "is for more than one" , "Exist; square measure" , "(They/you/we) exist" , "Is, in the plural" , "Unit of land measure equal to 100 square metres" .)