Burden we bear (4)
I believe the answer is:
onus
I believe this is a double definition.
'burden' is the first definition.
(I know that burden can be written as onus)
'we bear' is the second definition.
(we carry anything on us)
(Other definitions for onus that I've seen before include "Burden, duty" , "albatross?" , "Obligation - charge" , "Encumbrance" , "Weight of responsibility" .)