Free half of beer for the chap in the saddle (5)
I believe the answer is:
rider
'chap in the saddle' is the definition.
The definition and answer can be both people as well as being singular nouns.
Maybe you can see an association between them that I don't see?
'free half of beer' is the wordplay.
'free' becomes 'rid' (to be free of something is to be rid of it).
'half of' suggests halving the letters.
'beer' cut in half is 'er'.
'rid'+'er'='RIDER'
'for the' acts as a link.
Can you help me to learn more?
(Other definitions for rider that I've seen before include "Condition added to something already agreed" , "Traveller on horseback" , "Comment from jury" , "Stipulation" , "Revere, for example" .)