Adopting new top speed, charges hurdles (6)
I believe the answer is:
fences
'hurdles' is the definition.
The answer and definition can be both man-made objects as well as being plural nouns.
Maybe there's an association between them I don't understand?
'adopting new top speed charges' is the wordplay.
'adopting' indicates putting letters inside (inserted letters are taken on or adopted).
'new' becomes 'n' (abbreviation as in New Testament NT).
'top speed' becomes 'c' (c can mean the speed of light).
'charges' becomes 'fees' (fee is a kind of charge).
'n'+'c'='nc'
'nc' put within 'fees' is 'FENCES'.
Can you help me to learn more?
(Other definitions for fences that I've seen before include "Barriers to keep in or out" , "Good ones make good neighbours, it's said" , "items for negotiation" , "Engages in swordplay or processes stolen goods" , "Barriers that enclose" .)