Poet whose writings have value? (10)
I believe the answer is:
wordsworth
'poet' is the definition.
(William Wordsworth, 1770-1850)
'writings have value?' is the wordplay.
'writings' becomes 'words' (words may be written).
'have' is a charade indicator (letters next to each other).
'value?' becomes 'worth' (value is a kind of worth).
'words'+'worth'='WORDSWORTH'
'whose' acts as a link.
(Other definitions for wordsworth that I've seen before include "writer" , "Romantic poet" , "Poet (of the 20s)" .)