Highest point; child's toy (3)
I believe the answer is:
top
I believe this clue is a double definition.
'highest point' is the first definition.
(I've seen this before)
'child's toy' is the second definition.
(I've seen this in another clue)
(Other definitions for top that I've seen before include "Children's toy" , "Highest part" , "Peak; beat" , "Highest, child's toy" , "Acme or apex" .)