Bone with small top joined to bone with no name (7)
I believe the answer is:
scapula
'bone' is the definition.
(I know that Scapula is a type of bone)
'small top joined to bone with no name' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'top' becomes 'cap' (both can mean to beat or outdo).
'joined' means one lot of letters go next to another.
'to bone with no name' becomes 'ula' (I can't explain this - if you can you should believe this answer much more).
's'+'cap'+'ula'='SCAPULA'
'with' is the link.
(Other definitions for scapula that I've seen before include "Shoulder-bone" , "Flat, triangular human bone - cap Saul (anag)" , "Shoulder-blade" , "Shoulder blade" .)