Go round twisty ridge, making descent (8)
I believe the answer is:
pedigree
'descent' is the definition.
(I know that descent can be written as pedigree)
'go round twisty ridge' is the wordplay.
'go' becomes 'pee' (both can mean to urinate).
'round' is an insertion indicator.
'twisty' indicates anagramming the letters.
'ridge' with letters rearranged gives 'digre'.
'pee' placed around 'digre' is 'PEDIGREE'.
'making' acts as a link.
(Other definitions for pedigree that I've seen before include "What a mongrel doesn't have" , "Line of ancestry, particularly a distinguished one" , "(Pure) ancestry" , "Distinguished line of ancestors" , "bloodline" .)