Laughing talk? (3)
I believe the answer is:
gas
'talk?' is the definition.
(gas can mean to chat)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for gas that I've seen before include "Chatter vapidly" , "Carbon dioxide, say" , "rabbit" , "State of matter not solid or liquid" , "Fuel; idle talk" .)