Works out in cold on horses starting off (6)
I believe the answer is:
counts
'works' is the definition.
(count is a kind of work)
'out in cold on horses starting off' is the wordplay.
'out in cold' becomes 'c' (I can't justify this - if you can you should believe this answer much more).
'on' means one lot of letters go next to another.
'horses' becomes 'mounts' (mount is a kind of horse).
'starting off' means to remove the first letter (the starting letter is removed).
'mounts' with its first letter taken off is 'ounts'.
'c'+'ounts'='COUNTS'
Can you help me to learn more?
(Other definitions for counts that I've seen before include "Enumerates like minor aristocracy" , "Numbers" , "Determines the number of" .)