| OCTAHEDRALLY | • octahedrally adv. In an octahedral manner. • OCTAHEDRAL adv. having eight faces or sides. |
| OCTAHEDRITES | • OCTAHEDRITE n. a variety of anatase, crystallising in square bipyramids. |
| OCTAPEPTIDES | • octapeptides n. Plural of octapeptide. • OCTAPEPTIDE n. a protein fragment or molecule that consists of eight amino acids linked in a polypeptide chain. |
| OCTAPLOIDIES | • OCTAPLOIDY n. the condition of being octaploid, eightfold. |
| OCTASTICHONS | • OCTASTICHON n. a poem or stanza of eight lines, also OCTASTICH. |
| OCTASTICHOUS | • octastichous adj. (Botany) Having a phyllotaxis of eight leaves in each spiral around a stem. • OCTASTICHOUS adj. in eight rows, also OCTOSTICHOUS. |
| OCTASTROPHIC | • OCTASTROPHIC adj. consisting of eight strophes. |
| OCTILLIONTHS | • octillionths n. Plural of octillionth. • OCTILLIONTH n. one of an octillion equal parts. |
| OCTOGENARIAN | • octogenarian n. Synonym of eightysomething: a person between 80 and 89 years old. • octogenarian adj. Of or related to eightysomethings. • OCTOGENARIAN n. a person whose age is in the eighties. |
| OCTOGENARIES | • octogenaries n. Plural of octogenary. • OCTOGENARY n. someone eighty years old. |
| OCTOPETALOUS | • octopetalous adj. (Botany) Having eight petals. • OCTOPETALOUS adj. having eight petals. |
| OCTOSEPALOUS | • OCTOSEPALOUS adj. having eight sepals. |
| OCTOSTICHOUS | • octostichous adj. (Botany) octastichous. • OCTOSTICHOUS adj. in eight rows, also OCTASTICHOUS. |
| OCTOSYLLABIC | • octosyllabic adj. Containing eight syllables. • OCTOSYLLABIC adj. consisting of eight syllables. • OCTOSYLLABIC n. an octosyllabic line. |
| OCTOSYLLABLE | • octosyllable n. (Poetry) line of verse with eight syllables. • OCTOSYLLABLE n. a word or line of eight syllables. |
| OCTUPLICATES | • octuplicates n. Plural of octuplicate. • OCTUPLICATE n. one of eight corresponding things. |