| AUXOSPORE | • auxospore n. (Biology) A reproductive spore in diatoms that is formed by the union of two cells. • AUXOSPORE n. a diatom cell before its siliceous wall is formed. |
| BOXBOARDS | • boxboards n. Plural of boxboard. • BOXBOARD n. a kind of stiff paperboard. |
| BOXTHORNS | • boxthorns n. Plural of boxthorn. • BOXTHORN n. a thorny shrub with red berries. |
| EXOSPORAL | • exosporal adj. Relating to an exospore. • EXOSPORAL adj. of or like an exospore, the extreme outer layer of a spore. |
| EXOSPORES | • exospores n. Plural of exospore. • EXOSPORE n. the outer covering of a spore. |
| EXOSPORIA | • exosporia n. Plural of exosporium. • EXOSPORIUM n. the outermost layer of spores of certain bacilli. |
| EXPOSITOR | • expositor n. A person who expounds; a commentator. • EXPOSITOR n. one who, or that which, exposits. |
| ORTHOAXES | • ORTHOAXIS n. in crystallography, the orthodiagonal. |
| ORTHOAXIS | • ORTHOAXIS n. in crystallography, the orthodiagonal. |
| OXYMORONS | • oxymorons n. Plural of oxymoron. • OXYMORON n. (Greek) a self-contradictory expression. |
| OXYTROPES | • oxytropes n. Plural of oxytrope. • OXYTROPE n. a genus of plants in the legume family, including locoweed. |
| POORBOXES | • poorboxes n. Plural of poorbox. • poor␣boxes n. Plural of poor box. • POORBOX n. a box, esp. one in a church, used for the collection of alms or money for the poor. |
| PROTOXIDS | • protoxids n. Plural of protoxid. • PROTOXID n. that one of a series of oxides having the lowest proportion of oxygen, also PROTOXIDE. |
| STRONGBOX | • strongbox n. A sturdy box with a lock for storing valuables. • STRONGBOX n. a box for holding valuables. |
| TOXOCARAS | • TOXOCARA n. a kind of parasitic worm found in the intestines of dogs and cats. |
| WORKBOXES | • workboxes n. Plural of workbox. • WORKBOX n. a bag for holding work materials, also WORKBAG. |
| XEROSTOMA | • xerostoma n. (Obsolete) The condition of having a dry mouth. • XEROSTOMA n. excessive dryness of the mouth due to insufficient secretions, also XEROSTOMIA. |