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

rational¹ /rashˈə-nəl/

1. Of the reason
2. Endowed with reason
3. Agreeable to reason
4. Sane
5. Intelligent
6. Judicious
7. Commensurable with natural numbers

1. A rational being or quantity
2. (in pl) rational dress, ie knickerbockers instead of skirts for women (historical)

rationale /rash-ə-nälˈ/ noun

1. Underlying principle
2. A rational account
3. A theoretical explanation or solution

ratˈionalism noun

1. A system of belief regulated by reason, not authority
2. A disposition to apply to religious doctrines the same critical methods as to science and history, and to attribute all phenomena to natural rather than miraculous causes

ratˈionalist noun

rationalistˈic adjective

rationalistˈically adverb

rationality /rash-ən-alˈi-ti/ noun

1. The quality of being rational
2. The possession or due exercise of reason
3. Reasonableness

rationalization or rationalisation /rash-nəl-ī-zāˈshən/ noun

ratˈionalize or ratˈionalise transitive verb

1. To make rational
2. To free from irrational quantities
3. To conform to reason
4. To reorganize scientifically
5. To interpret rationalistically
6. To substitute conscious reasoning for unconscious motivation in explaining
7. To organize (an industry) so as to achieve greater efficiency and economy

1. To think or argue rationally or rationalistically
2. To employ reason, rationalism or rationalization

ratˈionalizer or ratˈionaliser noun

ratˈionally adverb

rational dress noun (historical)

Knickerbockers for women instead of skirts

rational horizon see under horizon

rational number noun

A number expressed as the ratio of two integers

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