Titian, easily irritated, blowing top (5)
I believe the answer is:
rusty
'titian' is the definition.
(thesaurus)
'easily irritated blowing top' is the wordplay.
'easily irritated' becomes 'crusty' (crusty can mean grumpy).
'blowing top' means to remove the first letter.
'crusty' with its first letter removed is 'RUSTY'.
(Other definitions for rusty that I've seen before include "Having a reddish-orange oxide coating" , "Oxidised, corroded" , "a bit faded" , "affected by inactivity" , "Antiquated" .)