State irked by decoration (8,5)
I believe the answer is:
victoria cross
'decoration' is the definition.
(I know that Victoria Cross is a type of decoration)
'state irked' is the wordplay.
I cannot quite see how this works, but
'state' could be 'victoria' (Victoria is an example) and 'victoria' is found within the answer.
The remaining letters 'cross' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'by' acts as a link.
Can you help me to learn more?
(Other definitions for victoria cross that I've seen before include "VC in full" , "Military medal" , "heroic achievement" , "Highest British military decoration for gallantry" , "award" .)