Dictionary
o•nus
Pronunciation: (ō'nus), [key]—
n.,
—pl. o•nus•es.
1. a difficult or disagreeable obligation, task, burden, etc.
2. burden of proof. Cf.
onus probandi.
3. blame or responsibility.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.