metre

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metre

1 (US), meter
1. a metric unit of length equal to approximately 1.094 yards
2. the basic SI unit of length; the length of the path travelled by light in free space during a time interval of 1/299 792 458 of a second. In 1983 this definition replaced the previous one based on krypton-86, which in turn had replaced the definition based on the platinum-iridium metre bar kept in Paris FORMULA

metre

2 (US), meter
1. Prosody the rhythmic arrangement of syllables in verse, usually according to the number and kind of feet in a line
2. Music another word (esp US) for time

meter, metre (m)

The International Standard unit of length; equal 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.