Quality testimonial at first (9)
I believe the answer is:
attribute
'quality' is the definition.
(I've seen this before)
'testimonial at first' is the wordplay.
'testimonial' becomes 'tribute' (synonyms).
'first' says to put letters next to each other.
'tribute' after 'at' is 'ATTRIBUTE'.
(Other definitions for attribute that I've seen before include "Credit - property" , "Quality, feature" , "Impute - quality" , "Ascribe (to a cause)" , "Character" .)