Spread gossip framing old lag (11)
I believe the answer is:
proliferate
'spread' is the definition.
(I've seen this before)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for proliferate that I've seen before include "Reproduce a lot" , "Reproduce rapidly" , "Mushroom" , "snowball" , "Multiply, expand" .)