Some meagre bed for a bird (5)
I believe the answer is:
grebe
'a bird' is the definition.
(type of bird)
'some meagre bed for' is the wordplay.
'some' indicates a hidden word (some parts of the word are used).
'GREBE' is hidden within 'meagre bed for'.
(Other definitions for grebe that I've seen before include "Swimmer" , "Freshwater diving bird" , "Diving waterbird" , "Diver" , "Crested water-bird" .)