Bird always without ID (5)
I believe the answer is:
eider
'bird' is the definition.
(eider is a kind of bird)
'always without id' is the wordplay.
'always' becomes 'eer' (poetic way of saying ever).
'without' means one lot of letters goes inside another ('without' can be similar in meaning to 'outside').
'eer' enclosing 'id' is 'EIDER'.
(Other definitions for eider that I've seen before include "Source of fine soft down" , "Reed I turn into a duck" , "Variety of duck" , "Large sea duck" , "Breed of duck" .)