Instrument or article with two round objects (7)
I believe the answer is:
theorbo
'instrument' is the definition.
(I've seen this before)
'article with two round objects' is the wordplay.
I cannot really see how this works, but
'article' could be 'the' (the 'definite article' part of speech) and 'the' is located in the answer.
'round' could be 'orb' and 'orb' is present in the answer.
A single letter 'o' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
'or' acts as a link.
(Other definitions for theorbo that I've seen before include "Old lute with two necks" , "Antique instrument" , "... something large to play" , "old instrument" , "Large lute" .)