Western horse lives awfully close to river (6)
I believe the answer is:
silver
'western horse' is the definition.
'silver' can be an answer for 'horse' (thesaurus). I am not certain of the 'western' bit.
'lives awfully close to river' is the wordplay.
'awfully' indicates an anagram.
'close to' indicates one should take the final letters (the close/ending of).
The final letter of 'river' is 'r'.
'lives' anagrammed gives 'silve'.
'silve'+'r'='SILVER'
Can you help me to learn more?
(Other definitions for silver that I've seen before include "symbolically a twenty-fifth" , "Change - Ag" , "Mineral ore, chemical symbol Ag" , "The finest conductor" , "Medal for the runner-up" .)