Be out of sleeping bag? That's odd (5)
I believe the answer is:
droll
'odd' is the definition.
(I've seen this in another clue)
'be out of sleeping bag?' is the wordplay.
'out of' suggests deleting specific letters ('out of' can mean no longer having).
'sleeping bag?' becomes 'bedroll' (sleeping bag is a kind of bedroll).
'bedroll' with 'be' taken away is 'DROLL'.
'that's' is the link.
(Other definitions for droll that I've seen before include "amusing, in a strange way" , "Clownish" , "Mildly amusing" , "Oddly amusing or comical" , "Large amount (of matter)" .)