Lean on Jag's boot, which gets bent (5)
I believe the answer is:
thing
'bent' is the definition.
(thesaurus)
'lean on jag's boot which' is the wordplay.
I cannot quite understand how this works, but
'lean' could be 'thin' (synonyms) and 'thin' is located in the answer.
A single letter 'g' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
'gets' is the link.
Can you help me to learn more?
(Other definitions for thing that I've seen before include "Object; gadget" , "Obsession" , "Individual object" , "A creature" , "Individual unit" .)