Ties Basil in knots to add security (9)
I believe the answer is:
stabilise
'add security' is the definition.
I can't judge whether this definition defines the answer.
'ties basil in knots' is the wordplay.
'in knots' is an anagram indicator (I've seen this in other clues).
'ties'+'basil'='tiesbasil'
'tiesbasil' with letters rearranged gives 'STABILISE'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for stabilise that I've seen before include "regulate equilibrium" , "Become less changeable" , "Make firm" , "Make of keep steady or balanced" , "get on an even keel" .)