Diamonds stolen from landowner's hiding places (5)
I believe the answer is:
lairs
'hiding places' is the definition.
'diamonds stolen from landowner's' is the wordplay.
'diamonds' becomes 'd' (abbreviation in bridge say).
'stolen from' suggests deleting specific letters.
'landowner's' becomes 'lairds' (Scottish term for a landowner).
'lairds' with 'd' removed is 'LAIRS'.
(Other definitions for lairs that I've seen before include "retreats" , "Places to hide" , "forms etc" , "Scottish landowners" , "Habitations of wild animals" .)