In simple terms, tenanted (3)
I believe the answer is:
let
'tenanted' is the definition.
(I've seen this in another clue)
'in simple terms' is the wordplay.
'in' says the answer is hidden in the clue.
'LET' is hidden in the letters of 'simple terms'.
(Other definitions for let that I've seen before include "Rent out: grant" , "Won't stop you" , "Allow or lease" , "Umpire's decision" , "inefficient service" .)