- late 14c., orange bright star in the constellation Bootes (also used of the whole constellation), from Latin Arcturus, from Greek Arktouros, literally "guardian of the bear" (the bright star was anciently associated with nearby Ursa Major, the "Big Dipper," which it seems to follow across the sky). For first element see arctic; second element is Greek ouros "watcher, guardian, ward," from PIE root *wer- (4) "perceive" (see ward (n.)). It is fourth-brightest of the fixed stars. The double nature of the great bear/wagon (see Big Dipper) has given two different names to the constellation that follows it: Arktouros "bear-ward" and Bootes "the wagoner."
Arcturus in the Bible (Job ix.9 and xxxviii.32) is a mistranslation by Jerome (continued in KJV) of Hebrew 'Ayish, which refers to what we see as the "bowl" of the Big Dipper. In Israel and Arabia, the seven stars of the Great Bear seem to have been a bier (the "bowl") followed by three mourners. In the Septuagint it was translated as Pleiada, which is equally incorrect.