Very old article, quite flexible (7)
I believe the answer is:
antique
'very old' is the definition.
(I've seen this before)
'article quite flexible' is the wordplay.
'article' becomes 'an' (indefinite article).
'flexible' indicates an anagram (the word is bent into a new form).
'quite' anagrammed gives 'tique'.
'an'+'tique'='ANTIQUE'
(Other definitions for antique that I've seen before include "Veteran" , "Quite an old thing with age value" , "Age-old" , "Venerably old" , "Long-standing" .)