This is the 15923rd most frequent Polish word.
tlącego
"Tlącego" means "smoldering" or "glowing faintly."
Here, 'tlącego' is the present participle of the verb 'tlić się', meaning 'to smolder' or 'to glow faintly', describing the ember with an ongoing action.
Spoglądał na tlącego się w kominku żaru.
He looked at the ember glowing in the fireplace.
In this sentence, 'tlącego' modifies 'ogniska', describing the campfire with the aspect of faintly burning or smoldering.
Widziała iskry z tlącego się ogniska.
She saw sparks from the smoldering campfire.
'tlącego' here describes 'tytoniu' (tobacco) as undergoing the process of faint burning or smoldering, contributing to the sensory description.