On top of a spell of bowling (4)
I believe the answer is:
over
This clue is a quadruple definition!!
'on' is the first definition.
(over can mean on top of)
'top' is the second definition.
(I've seen this before)
'of' acts as a link.
'a spell' is the third definition.
The definition and answer can be both related to time as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
'of' acts as a link.
'bowling' is the fourth definition.
(cricket term)
Can you help me to learn more?
(Other definitions for over that I've seen before include "Finished -- as a remainder" , "See 19" , "Finished like round of bowling in cricket" , "Finished-up -left" , "Finished like bowling session" .)