The base forms of the above-mentioned words in the East and West Indo-European languages are given below:
Gk. arktos ‘bear, the northern constellation Ursa Major,’ argos ‘swift motion that causes flickering light, shining, bright,’ erythros ‘red,’ argyros ‘silver,’ ēlektron ‘amber, also shining metal,’ lysis ‘a loosening,’ lytos ‘loosed’; Lat. argentum ‘silver, silver work, silver money,’ arguere ‘make clear, make known, prove, declare, demonstrate,’ ruber ‘red,’ rubere ‘to be red,’ russus, ursus, electrum ‘alloy of gold and silver,’ arktos ‘bear, the northern constellation Ursa Major’; O.Span. raudano; Proto-G. rauthan; O.E. rudu ‘red color,’ readan; G. rost; Swed. ronn; Med.Lat. lacca; Port. lacca ‘resinous substance’; F. laque; M.Du. lijkmoes; Arab. anbar ‘ambergris, morbid secretion of sperm-whale intestines used in perfumes and cookery.’