Rosemary, say, in another bed (4)
I believe the answer is:
herb
'rosemary' is the definition.
(thesaurus)
'in another bed' is the wordplay.
'in' indicates a hidden word.
'HERB' is hidden in the letters of 'another bed'.
'say' is the link.
(Other definitions for herb that I've seen before include "Simple" , "Useful or edible plant" , "Marjoram, say" , "Aromatic plant used in cookery" , "Eg, sage" .)