Vexed Irish seen by King Edward (5)
I believe the answer is:
irked
'vexed' is the definition.
(I've seen this in another clue)
'irish seen by king edward' is the wordplay.
'irish' becomes 'IR' (abbreviation).
'seen by' is a charade indicator (letters next to each other).
'king' becomes 'K' (abbreviation for king in chess).
'edward' becomes 'Ed' (short for Edward).
'ir'+'k'+'ed'='IRKED'
(Other definitions for irked that I've seen before include "Irritated - bothered" , "Galled" , "Bugged" , "Wound" , "Distressed" .)