Inherited from Middle Russian селитра (selitra) (since 1596), from Old Ruthenian селитра (selitra) (since 1565, whence Ukrainian селітра (selitra)), from earlier салитра (salitra) (att. in 1517 in Skaryna's Proverbs). Further origin unclear but akin to Middle Polish saletra (whence Old Ruthenian салетра (saletra) and Belarusian салетра (saljetra)), Old Polish sanletra, Old Czech salnitr, sanitr, sanytr, Bavarian Salitter, Middle High German saliter, salniter, Serbo-Croatian са̀литра, Spanish salitre, Catalan salnitre, Latin sal nitrum (which is from sal and nitrum, see there for further etymology).
Displaced earlier Middle Russian ямчуга (jamčuga) during the 17th century.
сели́тра • (selítra) f inan (genitive сели́тры, uncountable)