Perturb (7)
'perturb' is the definition.
(I know that perturb can be written as trouble)
This is all the clue.
(Other definitions for trouble that I've seen before include "Difficulty; cause distress to" , "Discord" , "Distress, upset or worry" , "Anxiety - disturbance - problem" , "Effort - (cause of) worry" .)
'perturb' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for unnerve that I've seen before include "Disconcert, make ill at ease" , "Intimidate" , "Faze" , "Perturb" , "Discourage - demoralise" .)
'perturb' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for agitate that I've seen before include "Stir (up public opinion?)" , "Trouble, make nervous" , "'Stir, excite (7)'" , "Get upset" , "Stir vigorously" .)