Tot with adult leaving theatre (5)
I believe the answer is:
drama
'theatre' is the definition.
(thesaurus)
'tot with adult' is the wordplay.
'tot' becomes 'dram' (I've seen this before).
'with' means one lot of letters go next to another.
'adult' becomes 'a'.
'dram'+'a'='DRAMA'
'leaving' is the link.
(Other definitions for drama that I've seen before include "Literary genre for the stage" , "theatre production" , "Turbulent emotional episode" , "Work to be performed by actors" , "Play - big emotional scene" .)