Vocabulary : Horehound to Hornbeam

Horehound : A plant of the genus Marrubium (M. vulgare), which has a bitter taste, and is a weak tonic, used as a household remedy for colds, coughing, etc.
Horizon : The circle which bounds that part of the earth's surface visible to a spectator from a given point; the apparent junction of the earth and sky. ;; A plane passing through the eye of the spectator and at right angles to the vertical at a given place; a plane tangent to the earth's surface at that place; called distinctively the sensible horizon. ;; A plane parallel to the sensible horizon of a place, and passing through the earth's center; -- called also rational / celestial horizon. ;; The unbroken line separating sky and water, as seen by an eye at a given elevation, no land being visible. ;; The epoch or time during which a deposit was made. ;; The chief horizontal line in a picture of any sort, which determines in the picture the height of the eye of the spectator; in an extended landscape, the representation of the natural horizon corresponds with this line.
Horizontal : Pertaining to, or near, the horizon. ;; Parallel to the horizon; on a level; as, a horizontalline or surface. ;; Measured or contained in a plane of the horizon; as, horizontal distance.
Horizontality : The state or quality of being horizontal.
Horizontally : In a horizontal direction or position; on a level; as, moving horizontally.

Hormogonium : A chain of small cells in certain algae, by which the plant is propogated.
Hormone : A chemical substance formed in one organ and carried in the circulation to another organ on which it exerts a stimulating effect; thus, according to Starling, the gastric glands are stimulated by a hormone from the pyloric mucous membrane.
Horn : A hard, projecting, and usually pointed organ, growing upon the heads of certain animals, esp. of the ruminants, as cattle, goats, and the like. The hollow horns of the Ox family consist externally of true horn, and are never shed. ;; The antler of a deer, which is of bone throughout, and annually shed and renewed. ;; Any natural projection or excrescence from an animal, resembling or thought to resemble a horn in substance or form; esp.: (a) A projection from the beak of a bird, as in the hornbill. (b) A tuft of feathers on the head of a bird, as in the horned owl. (c) A hornlike projection from the head or thorax of an insect, or the head of a reptile, or fish. (d) A sharp spine in front of the fins of a fish, as in the horned pout. ;; An incurved, tapering and pointed appendage found in the flowers of the milkweed (Asclepias). ;; Something made of a horn, or in resemblance of a horn ;; A wind instrument of music; originally, one made of a horn (of an ox or a ram); now applied to various elaborately wrought
Hornbeak : A fish. See Hornfish.
Hornbeam : A tree of the genus Carpinus (C. Americana), having a smooth gray bark and a ridged trunk, the wood being white and very hard. It is common along the banks of streams in the United States, and is also called ironwood. The English hornbeam is C. Betulus. The American is called also blue beech and water beech.