Come in again (2-5)
'come in again' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for re-enter that I've seen before include "Go back in" , "Come or go in again" , "compete again" , "Come back inside" .)
'come in again' is the definition.
('enter' can be a synonym for 'come in' so perhaps 'reenter' is OK for 'come in again')
This is all the clue.
(Other definitions for reenter that I've seen before include "Penetrate again" , "Come back inside" , "Go/come in again" , "Terrene (anag.)" , "Go in again" .)