Glen met an absurd fellow (9)
I believe the answer is:
gentleman
'fellow' is the definition.
(I've seen this before)
'glen met an absurd' is the wordplay.
'absurd' is an anagram indicator.
'glen'+'met'+'an'='glenmetan'
'glenmetan' is an anagram of 'GENTLEMAN'.
(Other definitions for gentleman that I've seen before include "Courteous fellow" , "A man of refinement" , "-'s -; - farmer" , "Polite, kind or upper-class fellow" , "Courteous male" .)