smolder

verb

1. (US, intransitive)To burn with no flame and little smoke.

   “The remains of the bonfire were left to smolder for hours.”

   “Our quiuering Lances ſhaking in the aire, And bullets like Ioues dreadfull Thunderbolts, Enrolde in flames and fiery ſmoldering miſtes, Shall threat the Gods more than Cyclopian warres, […]”

   “Behind him, where the deer had been, smoldered a large circle of grass and trees.”

2. (figuratively, intransitive)To show signs of repressed anger or suppressed mental turmoil or other strong emotion, such as passion.
3. (figuratively, intransitive)To exist in a suppressed or hidden state.

noun

1. The act of smoldering or something that smolders.

   “And she’s got a great scene partner in Stevens, refining his star power into a just slightly, almost imperceptibly mechanical approximation of Don Juan smolder. He lets us admire the interface and still see the code ticking away underneath it.”