It seems we bear this burden! (4)
I believe the answer is:
onus
'this burden' is the definition.
(synonyms)
'it seems we bear' is the wordplay.
I cannot really see how this works, but
'we' could be 'us' and 'us' is present in the answer.
The remaining letters 'on' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for onus that I've seen before include "'Burden, load (4)'" , "Encumbrance" , "Duty or responsibility" , "Weight of responsibility" , "'Burden, of proof (4)'" .)