Seize woman not fully identified (5)
I believe the answer is:
annex
'seize' is the definition.
(I know that annex is a kind of seize)
'woman not fully identified' is the wordplay.
'woman' becomes 'Anne' (woman's name).
'not fully' means to remove the last letter.
'identified' becomes 'ex' (I can't justify this - if you can you should give a lot more credence to this answer).
'anne' with its final letter taken away is 'ann'.
'ann'+'ex'='ANNEX'
Can you help me to learn more?
(Other definitions for annex that I've seen before include "Appropriate" , "Grab" , "Join - add" , "Attach, invade" , "Extension to a main building" .)