Where to put your feet up (8)
I believe the answer is:
stirrups
'where to put your feet' is the definition.
The definition suggests a singular noun but the answer is a plural noun.
'up' is the wordplay.
I cannot really understand how this works, but
'up' is within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for stirrups that I've seen before include "Riders' foot-rests" , "Metal loops for a rider" , "Riding equipment" , "footholds" , "Horse riders put their feet in them" .)