САЖА _|_ SOOT / SAZHA [ˈsaʐə]
Hint with an alternative definition: it is such a soot or ash-like smutch produced by the incomplete combustion session of charcoal in a chimney. It is used to make pigments and ink (pen-juice).
Hints with translation + consonant words (by sounds or letters): from a sachet (a good dry powder) to a сажа (a bad useless powder)
Russian pro-tip: то что сожжено и осело от жара
Mental visualization: C (pipe) + a (black smoke) + Ж (two candelabra) + a (black smoke)