Temperamental rodent keeps swishing tail (8)
I believe the answer is:
volatile
'temperamental' is the definition.
(thesaurus)
'rodent keeps swishing tail' is the wordplay.
I cannot quite understand how this works, but
an anagram of 'tail' is 'lati' which is located in the answer.
'rodent' could be 'vole' (vole is a kind of rodent) and 'vole' is located in the leftover letters.
This accounts for all the letters.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for volatile that I've seen before include "Fickle; evaporating easily" , "Liable to unpredictable change" , "A live lot being changeable" , "Unstable and liable to change" , "Easily vaporised" .)