Merriam-Webster's Collegiate® Dictionary, 11th Edition
GLOW
I. intransitive verb see: yellow Date: before 12th century
1. to shine with or as if with an intense heat , b. to have a rich warm typically ruddy color , flush , blush ,
2. to experience a sensation of or as if of heat , to show exuberance or elation , glowingly adverb
II. noun
Date: 1600
brightness or warmth of color,
2. warmth of feeling or emotion, a sensation of warmth ,
3. the state of glowing with heat and light, light such as is emitted by a solid body heated to luminosity ; incandescence