celestial horizon see horizon

celestial latitude see latitude

celestial longitude see longitude

celestial mechanics singular noun (astronomy)

The study of the motions of celestial objects in gravitational fields, esp, as by Newton, satellite and planetary motion in the solar system

celestial navigation noun

Navigation by the stars, etc (also astronavigation)

celestial poles plural noun (astronomy)

The two points at which the earth's axis, extended indefinitely, cuts the celestial sphere

celestial sphere noun (astronomy)

An imaginary sphere of infinite radius, of which the observer is the centre, onto which stars and other celestial bodies are projected

horizon /hə-rīˈzən/

1. The line at which earth and sky seem to meet (called the sensible horizon, apparent horizon or visible horizon)
2. A plane through the earth's centre parallel to the sensible horizon (called the rational horizon), or the great circle in which it meets the heavens (celestial horizon; astronomy)
3. A horizontal reflecting surface, eg of mercury, used as a substitute for the horizon in taking an observation (an artificial horizon)
4. A stratigraphical level, characterized generally by some particular fossil or fossils (geology), by a different physical property of the soil (soil science), or by artefacts characteristic of a particular culture or period (archaeology)
5. A level line or surface (anatomy)
6. (often pl) the limit of one's experience or mental vision

horizontal /hor-i-zontˈl/ adjective

1. Relating to the horizon
2. Parallel to the horizon
3. Level
4. Near the horizon
5. Measured in the plane of the horizon
6. Applying equally to all members of a group, aspects of an activity, etc
7. Of relationships between separate groups of equal status or stage of development
8. Denoting a balance sheet in which assets are set out in one column, and equity and liabilities in another, side by side (accounting)

1. A horizontal line, position or object
2. (also horizontal scrub) a large Tasmanian shrub, whose stem and branches ascend and then grow horizontally to form a dense mass of boughs and foliage

horizontalˈity noun

horizonˈtally adverb

horizontal bar noun (gymnastics)

A steel bar used for swinging and vaulting exercises