unglowing
/ˈʌŋˌɡloʊɪŋ/Definitions
1. adjective
not giving off light or heat; extinguished or having little or no glow
“The unglowing embers of the fire were barely visible in the dark room.”
2. adverb
in a way that is not giving off light or heat; in a state of being extinguished or having little or no glow
“The fire was burning unglowingly in the hearth.”