nitre

plural nitres

1. countableuncountableUK standard spelling of niter.

   The best yellow on cotton is dyed with sugar, or nitre of lead and the bichromate of potass.

   1847, editorial staff, “To Dye Yellow Color”, in Scientific American, series 1, Volume 3, Issue 9, page 72

   2 more examples

   For though thou wash thee with nitre, and take thee much soap, yet thine iniquity is marked before me.

   1611, The Holy Bible, […] (King James Version), London: […] Robert Barker, […], →OCLC, Jeremiah 2:22

   Had he bought nitre before, I have since tried to recall and I cannot. It is a common enough article and I sell it every day.

   1923, Ernest Bramah [pseudonym; Ernest Brammah Smith], “(please specify the page)”, in The Eyes of Max Carrados, London: Grant Richards, →OCLC