Imagine chat (11)

I believe the answer is:

confabulate

I'm a little stuck... Click here to teach me more about this clue!

This clue could be a double definition.

'imagine' is the first definition.
Although both the answer and definition are verbs in their base form, I cannot see how they can define each other.

'chat' is the second definition.
(synonyms)

Can you help me to learn more?

I've seen this clue in The Sunday Times and The Times.

Want a hint initially instead of a full solution? Install my app