glass (n.)youdaoicibaDictYouDict[glass 词源字典]
Old English glæs "glass; a glass vessel," from Proto-Germanic *glasam "glass" (cognates: Old Saxon glas, Middle Dutch and Dutch glas, German Glas, Old Norse gler "glass, looking glass," Danish glar), from PIE *ghel- (2) "to shine," with derivatives referring to bright materials and gold (cognates: Latin glaber "smooth, bald," Old Church Slavonic gladuku, Lithuanian glodus "smooth"). The PIE root also is the ancestor of widespread words for gray, blue, green, and yellow, such as Old English glær "amber," Latin glaesum "amber" (which might be from Germanic), Old Irish glass "green, blue, gray," Welsh glas "blue."

Restricted sense of "drinking glass" is from early 13c. and now excludes other glass vessels. Meaning "a glass mirror" is from 14c. Meaning "glass filled with running sand to measure time" is from 1550s; meaning "observing instrument" is from 1610s.[glass etymology, glass origin, 英语词源]