Valuable question about fragment (6)
I believe the answer is:
worthy
'valuable' is the definition.
(associated in meaning)
'question about fragment' is the wordplay.
'question' becomes 'why' (why is a question word).
'about' is an insertion indicator.
'fragment' becomes 'ort' (I've seen this before).
'why' placed around 'ort' is 'WORTHY'.
(Other definitions for worthy that I've seen before include "Suitable; deserving effort" , "Admirable, excellent or deserving" , "esteemed dignitary" , "American state, capital Montgomery" , "valuable" .)