1. A solid body standing on a triangular, square, or polygonal base, and terminating in a point at the top; especially, a structure or edifice of this shape.
2. Geom. A solid figure contained by a plane rectilineal figure as base and several triangles which have a common vertex and whose bases are sides of the base.
3. pl. Billiards The game of pool in which the balls are placed in the form of a triangle at spot. [Eng.]
Altitude of a pyramid Geom., the perpendicular distance from the vertex to the plane of the base.
Axis of a pyramid Geom., a straight line drawn from the vertex to the center of the base.
Earth pyramid. Geol. See Earth pillars, under Earth.
Right pyramid Geom. a pyramid whose axis is perpendicular to the base.
1. The globe or planet which we inhabit; the world, in distinction from the sun, moon, or stars. Also, this world as the dwelling place of mortals, in distinction from the dwelling place of spirits.
That law preserves the earth a sphere
And guides the planets in their course. --S. Rogers.
In heaven, or earth, or under earth, in hell. --Milton.
2. The solid materials which make up the globe, in distinction from the air or water; the dry land.
God called the dry land earth. --Gen. i. 10.
He is pure air and fire, and the dull elements of earth and water never appear in him. --Shak.
3. The softer inorganic matter composing part of the surface of the globe, in distinction from the firm rock; soil of all kinds, including gravel, clay, loam, and the like; sometimes, soil favorable to the growth of plants; the visible surface of the globe; the ground; as, loose earth; rich earth.
Give him a little earth for charity. --Shak.
4. A part of this globe; a region; a country; land.
Would I had never trod this English earth. --Shak.
5. Worldly things, as opposed to spiritual things; the pursuits, interests, and allurements of this life.
Our weary souls by earth beguiled. --Keble.
6. The people on the globe.
The whole earth was of one language. --Gen. xi. 1.
7. Chem. (a) Any earthy-looking metallic oxide, as alumina, glucina, zirconia, yttria, and thoria. (b) A similar oxide, having a slight alkaline reaction, as lime, magnesia, strontia, baryta.
8. A hole in the ground, where an animal hides himself; as, the earth of a fox.
They [ferrets] course the poor conies out of their earths. --Holland.
9. Elec. The connection of any part an electric conductor with the ground; specif., the connection of a telegraph line with the ground through a fault or otherwise.
Note: ☞ When the resistance of the earth connection is low it is termed a good earth.
Note: ☞ Earth is used either adjectively or in combination to form compound words; as, earth apple or earth-apple; earth metal or earth-metal; earth closet or earth-closet.
Adamic earth, Bitter earth, Bog earth, Chian earth, etc. See under Adamic, Bitter, etc.
Alkaline earths. See under Alkaline.
Earth apple. Bot. (a) A potato. (b) A cucumber.
Earth auger, a form of auger for boring into the ground; -- called also earth borer.
Earth bath, a bath taken by immersing the naked body in earth for healing purposes.
Earth battery Physics, a voltaic battery the elements of which are buried in the earth to be acted on by its moisture.
Earth chestnut, the pignut.
Earth closet, a privy or commode provided with dry earth or a similar substance for covering and deodorizing the fæcal discharges.
Earth dog Zoöl., a dog that will dig in the earth, or enter holes of foxes, etc.
Earth hog, Earth pig Zoöl., the aard-vark.
Earth hunger, an intense desire to own land, or, in the case of nations, to extend their domain.
Earth light Astron., the light reflected by the earth, as upon the moon, and corresponding to moonlight; -- called also earth shine. --Sir J. Herschel.
Earth metal. See 1st Earth, 7. Chem.
Earth oil, petroleum.
Earth pillars or Earth pyramids Geol., high pillars or pyramids of earth, sometimes capped with a single stone, found in Switzerland. --Lyell.
Earth pitch Min., mineral tar, a kind of asphaltum.
Earth quadrant, a fourth of the earth's circumference.
Earth table Arch., the lowest course of stones visible in a building; the ground table.
On earth, an intensive expression, oftenest used in questions and exclamations; as, What on earth shall I do? Nothing on earth will satisfy him. [Colloq.]