Slide round top (3)
I believe the answer is:
lid
'top' is the definition.
(I know that lid is a type of top)
'slide' is the wordplay.
'LID' is hidden in amongst the letters.
But, I am not sure how this is indicated.
'round' is the link.
Can you help me to learn more?
(Other definitions for lid that I've seen before include "Cover from gliders" , "Cap or top for container" , "Kind of cover, may be hinged" , "Removable cover of a container" , "Hinged or removable cover as for bottle" .)