An Etymological Dictionary of the German Language/Annotated/Glas
Glas, neuter, ‘glass, tumbler,’ from the equivalent Old High German and Middle High German glas, neuter; a common Teutonic word unknown to the other Aryan groups; compare Old Saxon gles, Dutch glas, Anglo-Saxon glæs, English glass; allied to Old Icelandic gler, neuter, ‘glass,’ with the change of s to r, which proves the word to be primitively Teutonic (*glaza- and *glasa- in Gothic). Hence it is not very probable that the Teutonic word was borrowed, although glass itself was imported by the Phœnicians. The Old Teutonic term for amber (Latin glêsum) is likewise primitively allied; compare Anglo-Saxon glæ̂re, ‘resin of trees.’ See the following word.