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' means one lot of letters go next to another.
'tribute' put 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" .)