Jeer when son falls down and gets behind (4)
I believe the answer is:
lags
'gets behind' is the definition.
(I've seen this in another clue)
'jeer when son falls down' is the wordplay.
I cannot quite understand how this works, but
'son' could be 's' (genealogical abbreviation for son) and 's' is located in the answer.
The remaining letters 'lag' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'and' acts as a link.
Can you help me to learn more?
(Other definitions for lags that I've seen before include "Drag's one's feet" , "Delays" , "Hangs back" , "Convicts" , "Dawdles" .)