| GAYFEATHERS | • gayfeathers n. Plural of gayfeather. |
| GNETOPHYTES | • gnetophytes n. Plural of gnetophyte. • GNETOPHYTE n. a type of plant including welwitschia. |
| GRAYWETHERS | • graywethers n. Plural of graywether. • GRAYWETHER n. a sandstone boulder of South England, also GREYWETHER. |
| GREYWETHERS | • greywethers n. Plural of greywether. • GREYWETHER n. a sandstone boulder of South England, also GRAYWETHER. |
| HERESIOLOGY | • heresiology n. The study of heresy. • HERESIOLOGY n. the study of heresies. |
| HONEYGUIDES | • honeyguides n. Plural of honeyguide. • honey␣guides n. Plural of honey guide. • HONEYGUIDE n. an African bird that guides men and ratels to honey. |
| HYDROGENASE | • hydrogenase n. (Biochemistry) Any enzyme that catalyzes the reduction of a substrate by the reversible oxidation of hydrogen. • HYDROGENASE n. an enzyme that catalyzes hydrogen formation in certain microorganisms. |
| HYDROGENISE | • hydrogenise v. (Transitive, British spelling, dated) Alternative spelling of hydrogenize. • HYDROGENISE v. to hydrogenate, also HYDROGENIZE. |
| HYETOLOGIES | • HYETOLOGY n. the science of rainfall. |
| HYGROMETERS | • hygrometers n. Plural of hygrometer. • HYGROMETER n. an instrument for measuring air moisture. |
| HYLOGENESES | • HYLOGENESIS n. the origin of matter. |
| HYLOGENESIS | • hylogenesis n. (Philosophy) The origin of matter. • HYLOGENESIS n. the origin of matter. |
| HYPERGAMIES | • hypergamies n. Plural of hypergamy. • HYPERGAMY n. the marriage of a man to a woman of lower status. |
| HYPNOGENIES | • HYPNOGENY n. production of the hypnotic state, also HYPNOGENESIS. |
| HYSTEROGENY | • HYSTEROGENY n. the generation of hysteria. |
| PHYLOGENIES | • phylogenies n. Plural of phylogeny. • PHYLOGENY n. the evolutionary development of a species, a group of organisms, or a particular feature of an organism. |
| PHYTOGENIES | • phytogenies n. Plural of phytogeny. • PHYTOGENY n. the doctrine of the generation of plants. |
| YESTERNIGHT | • yesternight adv. (Archaic) Last night. • yesternight n. (Archaic) A preceding night. • YESTERNIGHT n. (dialect) last night. |
| ZYGOSPHENES | • zygosphenes n. Plural of zygosphene. • ZYGOSPHENE n. a median process on the front part of the neural arch of the vertebrae of most snakes and some lizards, which fits into a fossa, called the zygantrum, on the back part of the arch in front. |