Man climbing trail — before he makes this? (7)
I believe the answer is:
descent
'before he makes this?' is the definition.
The definition suggests a singular noun which matches the answer.
'man climbing trail' is the wordplay.
'man' becomes 'Ed' (short for Edward).
'climbing' shows that the letters should be reversed in order (in a down clue, letters climb up).
'trail' becomes 'scent' (an animal's trail is its scent).
'ed' reversed gives 'de'.
'de'+'scent'='DESCENT'
(Other definitions for descent that I've seen before include "Pedigree" , "Roots" , "Ancestry - downward move" , "Lineage" , "Ancestry -- downward movement" .)