What carer must do to make youngster take a seat (4-3)
I believe the answer is:
baby-sit
'what carer must do to' is the definition.
The definition suggests a singular noun but the answer is not.
'youngster take a seat' is the wordplay.
'youngster' becomes 'baby'.
'take a seat' becomes 'sit' (sit down on a seat).
'baby'+'sit'='BABY-SIT'
'make' acts as a link.
Can you help me to learn more?
(Other definitions for baby-sit that I've seen before include "Look after young children" , "Look after a young child" , "Look after youngsters" , "Take charge to allow parents to go out" , "Mind small children while parents have a night out" .)