Enquire at the weekend, perhaps, about rider (10)
I believe the answer is:
equestrian
'rider' is the definition.
(I know that equestrian is a type of rider)
'enquire at the weekend perhaps about' is the wordplay.
I cannot quite see how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is present in the answer.
'about' could be 'a' (abbreviation in Chambers) and 'a' is found within the answer.
'at' could be 'in' (synonymous in some cases - eg at school, in school) and 'in' is found within the remaining letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for equestrian that I've seen before include "Relating to horse riding" , "Horse-rider" , "Person on horseback" , "Horseman" , "Jockey" .)