Is there something in the wine I provided, old chap? (5)
I believe the answer is:
elder
'old chap?' is the definition.
(thesaurus)
'is there something' is the wordplay.
'is there' becomes 'eld' (I can't justify this - if you can you should give a lot more credence to this answer).
'something' becomes 'er' (I've seen this in other clues).
'eld'+'er'='ELDER'
'in the wine i provided' acts as a link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for elder that I've seen before include "More aged; tree" , "Tree and Mormon church officer" , "Tie up" , "Shrub - church official" , "comparatively aged" .)