| the fundamental unit of length in the metric system, equivalent to 39.37 U.S. inches, originally intended to be, and being very nearly, equal to one ten-millionth of the distance from the equator to the pole measured on a meridian: defined from 1889 to 1960 as the distance between two lines on a platinum-iridium bar (the “International Prototype Meter”) preserved at the International Bureau of Weights and Measures near Paris; from 1960 to 1983 defined as 1,650,763.73 wavelengths of the orange-red radiation of krypton 86 under specified conditions; and now defined as 1/299,792,458 of the distance light travels in a vacuum in one second. Abbreviation: m |
| 1. | Music.
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| 1. | an instrument for measuring, esp. one that automatically measures and records the quantity of something, as of gas, water, miles, or time, when it is activated. |
| 2. | parking meter. |
| 3. | to measure by means of a meter. |
| 4. | to process (mail) by means of a postage meter. |
me·tre 1 (mē'tər) n. Chiefly British Variant of meter1. |
me·tre 2 (mē'tər) n. Chiefly British Variant of meter2. |
The basic unit of length in the metric system; it was originally planned so that the circumference of the Earth would be measured at about forty million meters. A meter is 39.37 inches. Today, the meter is defined to be the distance light travels in 1 / 299,792,458 seconds.
meter me·ter (mē'tər)
n.
Abbr. m
The standard unit of length in the International System of Units that is equivalent to 39.37 inches.
metre unit
(US "meter") The fundamental SI unit of length.
From 1889 to 1960, the metre was defined to be the distance between two scratches in a platinum-iridium bar kept in the vault beside the Standard Kilogram at the International Bureau of Weights and Measures near Paris.
This replaced an earlier definition as 10^-7 times the distance between the North Pole and the Equator along a meridian through Paris; unfortunately, this had been based on an inexact value of the circumference of the Earth.
From 1960 to 1984 it was defined to be 1650763.73 wavelengths of the orange-red line of krypton-86 propagating in a vacuum.
It is now defined as the length of the path traveled by light in a vacuum in the time interval of 1/299,792,458 of a second.
(1998-02-07)