Potash

[pot-ash] /ˈpɒtˌæʃ/

noun
1.
potassium carbonate, especially the crude impure form obtained from wood ashes.
2.
potassium hydroxide.
3.
the oxide of potassium, K 2 O.
4.
potassium, as carbonate of potash.
/ˈpɒtˌæʃ/
noun
1.
another name for potassium carbonate, esp the form obtained by leaching wood ash
2.
another name for potassium hydroxide
3.
potassium chemically combined in certain compounds: chloride of potash
n.

1751, earlier -pot-ashes (1640s), a loan-translation of older Dutch potaschen, literally “pot ashes” (16c.); so called because it was originally obtained by soaking wood ashes in water and evaporating the mixture in an iron pot. Cf. German Pottasche, Danish potaske, Swedish pottaska, all also from Dutch. See also potassium. French potasse (1570s), Italian potassa are Germanic loan-words. The original plural was pot-ashes.

potash pot·ash (pŏt’āsh’)
n.

potash
(pŏt’āsh’)
Any of several chemical compounds that contain potassium, especially potassium carbonate (K2CO3), which is a strongly alkaline material obtained from wood ashes and used in fertilizers.