Knotting of a rope isn't frequent (9)
I believe the answer is:
patronise
'frequent' is the definition.
(I know that frequent can be written as patronise)
'knotting of a rope isn't' is the wordplay.
'knotting of' is an anagram indicator (I've seen 'knot' mean this (letters are tangled up)).
'a'+'rope'+'isnt'='aropeisnt'
'aropeisnt' with letters rearranged gives 'PATRONISE'.
(Other definitions for patronise that I've seen before include "Give encouragement or treat with condescension" , "champion" , "Sponsor" , "Frequent as customer" , "Talk down to" .)