This is the 16476th most frequent Russian word.
сажи
The Russian word "сажи" means "soot" in English.
Here, 'сажи' is used to mean 'soot,' which refers to a substance produced by incomplete combustion.
В старинных лампах использовали сажи для создания света.
In old lamps, soot was used to create light.
In this sentence, 'сажи' again refers to 'soot' as a physical material utilized for its insulating properties.
Положи сажи ровным слоем, чтобы лучше утеплить.
Place the soot in an even layer to improve insulation.
Here, 'сажи' signifies 'soot' as the residue resulting from combustion, marking an aftermath.