Out of a black tower (6)
I believe the answer is:
abloom
'out' is the definition.
(I've seen this before)
'a black tower' is the wordplay.
'black' becomes 'b' (as in pencil classifications).
'tower' becomes 'loom' (synonyms).
'a'+'b'+'loom'='ABLOOM'
'of' is the link.
(Other definitions for abloom that I've seen before include "no longer buddy of Rose?" , "Healthy" , "full of colour" , "Flowering" , "covered in flowers?" .)