Without exception, pet with energy irritated corgi (9)
I believe the answer is:
categoric
'without exception pet with energy irritated corgi' is the definition.
I can't judge whether this defines the answer.
'pet with energy irritated corgi' is the wordplay.
'pet' becomes 'cat' (cats are often kept as pets).
'with' means one lot of letters goes inside another.
'energy' becomes 'e' (physics symbol as in E=mc2).
'irritated' is an anagram indicator (letters disturbed or irritated).
'corgi' with letters rearranged gives 'goric'.
'e' inserted within 'goric' is 'egoric'.
'cat'+'egoric'='CATEGORIC'
Can you help me to learn more?
(Other definitions for categoric that I've seen before include "Unqualified" , "Positive" , "Unambiguously direct" , "Unconditional" , "Absolute" .)