Arcturus

[ ahrk-too r-uh s, -tyoo r- ]

/ ɑrkˈtʊər əs, -ˈtyʊər- /

noun Astronomy.

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

Related forms

Arc·tu·ri·an, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for arcturus

By meridian altitude of Arcturus, camp is in latitude 31 degrees 34 minutes 28 seconds South.
Explorations in Australia|John Forrest
He placed the little detective in the focus of a telescope and turned it on Arcturus.
Scientific American Supplement, No. 288|Various
The next group, to which Capella and Arcturus belong, is also very numerous, and forms the solar type of stars.
Man's Place in the Universe|Alfred R. Wallace
Been computing the orbit of the wreckage of the Arcturus around Jupiter.
Spacehounds of IPC|Edward Elmer Smith

Years ago, in a time when we were very mad wags, Arcturus and myself met a gentleman from China who knew the language.
Roundabout Papers|William Makepeace Thackeray

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

Derived Forms

Arcturian, adjective

Word Origin for Arcturus

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

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

Science 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.