Angry at having a disastrous try-out! (5)
I believe the answer is:
ratty
'angry' is the definition.
(thesaurus)
'having a disastrous try-out' is the wordplay.
'having' becomes 'at' (I can't explain this - if you can you should believe this answer much more).
'a disastrous' indicates anagramming the letters.
'out' means one lot of letters goes inside another.
'try' is an anagram of 'rty'.
'at' inserted inside 'rty' is 'RATTY'.
'at' acts as a link.
Can you help me to learn more?
(Other definitions for ratty that I've seen before include "Bad-tempered, irritable as a rodent" , "his friend being a dangerous driver" , "Mole's friend (The Wind in the Willows)" , "Characteristic of pest" , "describing vermin" .)