We don't have synonyms for potass yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are potash, portass and potas.
(n) :
Obsolete form of potash. [The water-soluble part of wood ash, used for making soap and glass and as a fertilizer (chemically speaking, an impure form of potassium carbonate (K₂CO₃) mixed with other potassium salts).]
(n) :
Obsolete form of potash. [The water-soluble part of wood ash, used for making soap and glass and as a fertilizer (chemically speaking, an impure form of potassium carbonate (K₂CO₃) mixed with other potassium salts).]