Contribution to the park that ran round the town centre? (5)
I believe the answer is:
rowan
'contribution to the park that' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'ran round the town centre?' is the wordplay.
'round' is an insertion indicator.
'the town centre?' becomes 'ow' (central letters of the word 'town').
'ran' placed around 'ow' is 'ROWAN'.
Can you help me to learn more?
(Other definitions for rowan that I've seen before include "The mountain ash tree" , "Canterbury" , "Atkinson or Williams" , "Red-berried tree" , "Man" .)