Bad reaction of a grouser agitated about parking Sierra (4,6)
I believe the answer is:
sour grapes
'bad reaction' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'a grouser agitated about parking sierra' is the wordplay.
I cannot quite understand how this works, but
'a' is found in the answer.
'parking' could be 'p' (abbreviation on road signs) and 'p' is present in the answer.
an anagram of 'grouser' is 'sourgre' which is located in the left over letters.
'sierra' could be 's' (phonetic alphabet: alpha, bravo, charlie etc.) and 's' is present in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'of' is the link.
Can you help me to learn more?
(Other definitions for sour grapes that I've seen before include "Belittlement" , "Derision of the unattainable" , "Jealous resentment" , "Selfishly disparaging attitude" , "Affected disdain" .)