Legal Definitions - onus

Onus means a burden or a load. It can also mean a responsibility that is not enjoyable or easy to do.

• Carrying a heavy backpack all day is an onus.
• It is the onus of the parents to take care of their children.
• Proving that someone is guilty is the onus of the prosecution in a court case.

The first example shows how onus can refer to a physical burden. The second example shows how onus can refer to a responsibility that is not enjoyable. The third example shows how onus can refer to a legal responsibility.