| ONIE | • ONIE adj. (Scots) any, also ONY. | 
| ONION | • onion n. A monocotyledonous plant (Allium cepa), allied to garlic, used as vegetable and spice. • onion n. The bulb of such a plant. • onion n. (Uncountable) The genus Allium as a whole. | 
| ONIONED | • onioned adj. Flavoured or made with onion. • ONION v. to apply an onion, an edible bulb, to. | 
| ONIONIER | • onionier adj. Comparative form of oniony: more oniony. • ONIONY adj. like an onion. | 
| ONIONIEST | • onioniest adj. Superlative form of oniony: most oniony. • ONIONY adj. like an onion. | 
| ONIONING | • ONION v. to apply an onion, an edible bulb, to. | 
| ONIONS | • onions n. Plural of onion. • Onions n. Plural of Onion. • Onions prop.n. A surname from Welsh [in turn originating as a patronymic]. | 
| ONIONSKIN | • onionskin n. A thin, strong, light, translucent paper; used especially for making carbon copies. • onion␣skin n. Alternative form of onionskin (“kind of translucent paper”). • ONIONSKIN n. a very thin variety of paper. | 
| ONIONSKINS | • onionskins n. Plural of onionskin. • onion␣skins n. Plural of onion skin. • ONIONSKIN n. a very thin variety of paper. | 
| ONIONY | • oniony adj. Resembling an onion or onions, especially in terms of smell. • oniony adj. Resembling the satirical news website The Onion. • Oniony adj. Alternative form of oniony (“resembling the satirical news website The Onion”). | 
| ONIRIC | • oniric adj. Alternative form of oneiric. • ONIRIC adj. belonging to dreams, also ONEIRIC. | 
| ONISCOID | • oniscoid n. (Zoology) A member of the Oniscoidea; a woodlouse. • ONISCOID adj. like a woodlouse. | 
| ONIUM | • onium n. (Chemistry) any cation derived by the addition of a proton to the hydride of any element of the nitrogen… • onium n. (Chemistry) any organic derivative of these compounds. • onium n. (Physics) the bound pair of a particle and its antiparticle. | 
| ONIUMS | • oniums n. Plural of onium. • ONIUM n. a compound containing ions of the kind with names ending in -onium. |