To start, tie it in a knot! (8)
I believe the answer is:
initiate
'to start' is the definition.
('initiate' can be a synonym of 'start')
'tie it in a knot' is the wordplay.
'knot' indicates anagramming the letters (I've seen 'knotted' mean this).
'tie'+'it'+'in'+'a'='tieitina'
'tieitina' with letters rearranged gives 'INITIATE'.
(Other definitions for initiate that I've seen before include "having special knowledge" , "Start (something)" , "starter" , "Admit into closed society - beginner" , "found" .)