Gather round far end of water wagon (5)
I believe the answer is:
truck
'wagon' is the definition.
(thesaurus)
'gather round far end of water' is the wordplay.
'gather' becomes 'tuck' (synonyms).
'round' means one lot of letters goes inside another.
'far end of water' becomes 'r' (I can't explain this - if you can you should give a lot more credence to this answer).
'tuck' enclosing 'r' is 'TRUCK'.
Can you help me to learn more?
(Other definitions for truck that I've seen before include "Exchange" , "Freight vehicle" , "See 14" , "trolley" , "trade" .)