An Etymological Dictionary of the German Language/Annotated/glühen
glühen, verb, ‘to glow,’ from the equivalent Middle High German glüen, glüejen, Old High German gluoen, weak verb; corresponding to Anglo-Saxon glôwan, English to glow, Dutch gloeijen, Old Icelandic glóa, ‘to glow.’ From the Teutonic root glô, glê, are also derived Modern High German Glut, Middle High German and Old High German gluot, feminine, to which Dutch gloed, Anglo-Saxon gléd (Gothic *glô-di-), English dialectic gleed correspond, likewise Anglo-Saxon glôma, glômung, ‘twilight,’ English gloom, Old Icelandic glámr, ‘moon.’ With the Teutonic root gló, glê (from pre-Teutonic ghlū̆), Lithuanian zlejà, ‘twilight,’ is also connected.