Annoyed shopper starts to express dismay (6)
I believe the answer is:
narked
'annoyed' is the definition.
('nark' can be a synonym of 'annoy')
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for narked that I've seen before include "Annoyed - upset - irritated" , "Angry" , "Cross" , "Nettled" , "'Vexed, riled (6)'" .)