Definition of black salt in English:

black salt

noun

historical
  • Any of various inorganic salts that are naturally dark in colour, or are darkened by admixed charcoal, soot, etc.; specifically (in plural) impure potash obtained by leaching wood ash and evaporating the resulting solution (now historical).

Origin

Late Middle English; earliest use found in John Trevisa (c1342–?1402), translator. From black + salt, originally after post-classical Latin sal niger.

Pronunciation

black salt

/ˌblak ˈsɒlt//ˌblak ˈsɔːlt/