smol·der (US) or Brit smoul·der 
/ˈsmoʊldɚ/ verb
smol·ders; smol·dered; smol·der·ing /ˈsmoʊldɚ/ verb [no obj] 1 : to burn slowly without flames but usually with smoke
▪ The remains of the campfire smoldered. ▪ smoldering ruins ▪ a smoldering fire 2 literary a : to feel a strong emotion but keep it hidden
▪ He smoldered with lust. ▪ Her eyes smoldered with anger.
b : to be felt strongly by someone without being directly shown or expressed
▪ Anger smoldered in my heart. ▪ Their discontent smoldered [=simmered] for years. 3 : to be attractive in a sexy way
▪ He gave her a smoldering look. [=he looked at her in a very sexy way]
▪ The remains of the campfire smoldered. ▪ smoldering ruins ▪ a smoldering fire
▪ He smoldered with lust. ▪ Her eyes smoldered with anger.
b : to be felt strongly by someone without being directly shown or expressed
▪ Anger smoldered in my heart. ▪ Their discontent smoldered [=simmered] for years.
▪ He gave her a smoldering look. [=he looked at her in a very sexy way]
