Arcturus

[ ahrk-toor-uhs, -tyoor- ]

nounAstronomy.

a first-magnitude star in the constellation Boötes.

Origin of Arcturus

1352–75; <Latin <Greek Arktoûros, equivalent to árkt(os) bear + -oûros keeper; replacing Middle English arture<Middle French

Other words from Arcturus

Arc·tu·ri·an, adjective

Words Nearby Arcturus

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use Arcturus in a sentence

But a moment later he referred to the stupendous fact of Arcturus being fifty thousand times as big as the sun.
Mark Twain, A Biography, 1835-1910, Complete | Albert Bigelow Paine
If the axis of the earth pointed toward Arcturus instead of Polaris, would the seasons be any different from what they are now?
A Text-Book of Astronomy | George C. Comstock
Arcturus has been moving ever since the time of Job at the rate of probably more than 200 miles per second—possibly 300 miles.
The Popular Science Monthly, September, 1900 | Various
Papilio Arcturus and some allied species, are of a golden-green, changing to blue, or to glowing purple.
The Romance of Natural History, Second Series | Philip Henry Gosse
Years ago, Arcturus and myself met a gentleman from China who knew the language.
An English Grammar | W. M. Baskervill and J. W. Sewell

British Dictionary definitions for Arcturus

Arcturus

/ (ɑːkˈtjʊərəs) /

noun

the brightest star in the constellation Boötes: a red giant. Visual magnitude: –0.4; spectral type: K2III; distance: 37 light years

Origin of Arcturus

C14: from Latin, from Greek Arktouros, from arktos bear + ouros guard, keeper

Derived forms of Arcturus

Arcturian, adjective

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for Arcturus

Arcturus

[ ärk-tur′əs ]

A giant star in the constellation Boötes. It is the brightest star in the Northern Hemisphere and the fourth brightest star in the sky, with an apparent magnitude of 0.00. Scientific name: Alpha Boötes.

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