Understanding it's being snagged by (8,2)

'understanding' is the definition.
The answer and definition can be both related to thinking as well as being present participle verbs.
Maybe there's an association between them I don't understand?

'being snagged by' is the wordplay.
I cannot really understand how this works, but
'being' could be 'cat' (cat is a kind of being) and 'cat' is found within the answer.
This may be the basis of the clue (or it may be nonsense).

'it's' is the link.

Can you help me to learn more?