Is exultant about the many animals trapped (6)
I believe the answer is:
gloats
'is' is the definition.
Although both the answer and definition are verbs in their -s form, I cannot see how they can define each other.
'exultant about the many animals trapped' is the wordplay.
I cannot quite see how this works, but
'about' could be 'a' (abbreviation in Chambers) and 'a' is found within the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is located in the answer.
'many' could be 'l' and 'l' is found in the answer.
The remaining letters 'gos' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for gloats that I've seen before include "Is full of malicious delight" , "Indulges malicious pleasure" , "Crows" , "Is full of malicious pleasure" , "Exults with malicious delight" .)