onus
UK: ˈəʊnəs | US: ˈoʊnəs
n. a burden or responsibility
n. (law) the duty to prove something in a legal case
The word "onus" comes directly from Latin, where it meant "load" or "burden." It was adopted into English in the 17th century, retaining its original sense of a weighty responsibility. In legal contexts, it specifically refers to the obligation to provide proof (e.g., "onus of proof"). Unlike many Latin-derived words, "onus" has not been segmented further in English, as it functions as a single, indivisible morpheme.
The onus of completing the project fell entirely on her shoulders.
In court, the onus is on the prosecution to prove guilt beyond a reasonable doubt.
He felt the onus of his family's expectations weighing heavily on him.
The new policy shifts the onus of environmental compliance to manufacturers.
With great power comes the onus of greater responsibility.