Jingle object by the shaft (4)
I believe the answer is:
adit
'the shaft' is the definition.
(thesaurus)
'jingle object by' is the wordplay.
'jingle' becomes 'ad' (I can't explain this - if you can you should give a lot more credence to this answer).
'object' becomes 'it' (pronoun for an inanimate object).
'by' says to put letters next to each other.
'ad'+'it'='ADIT'
Can you help me to learn more?
(Other definitions for adit that I've seen before include "Horiz. mine entrance" , "Mine access passage" , "Pit access" , "Almost horizontal mine shaft" , "Passageway into a mine" .)