onus
UK[ˈəʊnəs]US[ˈoʊnəs]
n
something that is one's duty or responsibility
n
blame or responsibility for something
Etymology
The word 'onus' was borrowed directly from Latin, where it meant a literal "load" or "burden." This Latin term is believed to derive from the Proto-Indo-European root h₃enh₂-, meaning "to blame, to accuse," which also gave rise to the Sanskrit word 'enas' (sin, offense) and the Ancient Greek word 'ónos' (blame, reproach). The semantic journey from a physical "burden" to a metaphorical one of duty, obligation, or blame is a classic example of abstraction. In modern English, it retains this abstract sense, specifically denoting a duty, responsibility, or the burden of proof or blame in formal contexts.
Analysis
This word is a direct loanword from Latin and is not productively segmented using English morphemes. The entire word 'onus' is the Latin noun meaning "burden, load, task."
Examples
The onus is on the prosecution to prove the defendant's guilt beyond a reasonable doubt.
She felt the onus of managing the entire project alone.
The report places the onus for the environmental damage squarely on the corporation.