Saltpeter (noun)

1. A white crystalline powder, also known as potassium nitrate, that is used in many industries such as food preservation, fireworks, and gunpowder.
2. A salt of potassium, found naturally or obtained by leaching wood ashes, used in food preservation and fireworks.

Origin:

The word "saltpeter" is derived from the middle english word "saltpetre" from the old french "salpetre", and ultimately from the latin words "sal" meaning salt and "petra" meaning rock. it is a common name for potassium nitrate, a white crystalline powder that is used in many industries, such as food preservation, fireworks, and gunpowder.

Examples:

1. The saltpeter was an essential ingredient in the manufacture of gunpowder.
2. The saltpeter was used as a food preservative, preventing the growth of bacteria.
3. The saltpeter was used in fireworks to give them a bright and colorful explosion.
4. He was buying saltpeter for use in his homemade fireworks.
5. Saltpeter mines were important during the 19th century for production of gunpowder.