n. 1. a. A mineral deposit rich in sodium nitrate occurring naturally in Chile, Peru, and the southwest United States, and used as fertilizer, in explosives, and as a raw material for manufacturing nitric acid. b. See sodium nitrate. 2. a. The accretions of calcium carbonate in soil. b. See hardpan. [American Spanish, from Spanish, pebble in a brick, flake of lime, from cal, lime, from Latin calx, calc-, lime; see CALX.] |
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.