Blunder, cutting wrong ties in alarm (9)
I believe the answer is:
terrorise
'alarm' is the definition.
('alarm'->'terrorize' is in my internal thesaurus and 'ize'->'ise')
'blunder cutting wrong ties' is the wordplay.
'blunder' becomes 'error' (I've seen this before).
'cutting' means one lot of letters goes inside another (some letters cut their way into a word).
'wrong' indicates anagramming the letters.
'ties' with letters rearranged gives 'tise'.
'error' put within 'tise' is 'TERRORISE'.
'in' acts as a link.
(Other definitions for terrorise that I've seen before include "Spook" , "Panic" , "generate fear" , "Oppress by fear" , "Frighten greatly" .)