Replacement for rug or matting in gorge (9)
I believe the answer is:
surrogate
'gorge' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
'replacement for rug or matting in' is the wordplay.
'replacement for' indicates an anagram.
'matting' becomes 'sate' (I can't justify this - if you can you should give a lot more credence to this answer).
'in' is an insertion indicator.
'rug'+'or'='rugor'
'rugor' with letters rearranged gives 'urrog'.
'urrog' placed inside 'sate' is 'SURROGATE'.
Can you help me to learn more?
(Other definitions for surrogate that I've seen before include "Substitute fulfilling the role of another" , "Argues about rot with substitute or deputy" , "One standing in" , "(A) substitute in office" , "stand-in" .)