The quality is not entirely the same (5)
I believe the answer is:
equal
'same' is the definition.
(associated in meaning)
'the quality is not entirely' is the wordplay.
'is not entirely' indicates the answer is hidden within the clue.
'EQUAL' can be found hidden inside 'the quality'.
'the' is the link.
(Other definitions for equal that I've seen before include "On a par" , "Numerically identical" , "The same; fairly balanced" , "Level" , "What Orwell's animals were" .)