A marksman will find use for this sort of gift horse (9)
I believe the answer is:
foresight
'a marksman will find use for this sort of gift horse' is the definition.
The answer and definition can be both human attributes as well as being singular nouns.
Maybe you can see an association between them that I can't see?
'sort of gift horse' is the wordplay.
'sort of' is an anagram indicator.
'gift'+'horse'='gifthorse'
'gifthorse' anagrammed gives 'FORESIGHT'.
Can you help me to learn more?
(Other definitions for foresight that I've seen before include "Vision" , "Caution" , "Ability to anticipate" , "Clairvoyance" , "Prudence" .)