placer

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A glacial or alluvial deposit of sand or gravel containing eroded particles of valuable minerals.
2. n. A place where a placer deposit is washed to extract its mineral content.

Century Dictionary and Cyclopedia

1. n. One who places, locates, or sets.
2. n. In minning, a place where the superficial detritus is washed for gold or other valuable minerals: a word formerly in common use in California, but now nearly obsolete. Placer-minining has hardly auy other meaning in English than that of gold-washing, but it is not used in speaking of washing for gold by the hydraulic method. Washing for tin—a kind of mining not carried on in the United States—is called streaming.
3. n. In ceramics, a workman in a pottery who places the unburned ware in the saggars and arranges the saggars in the kiln.
4. In mining, to mine by the hydraulic process; wash out (gold) from a bank by a stream of water.

Wiktionary

1. n. mining A deposit of sand or earth in a river-bed etc. which contains particles of gold or other precious minerals.
2. n. One who places or arranges something.
3. n. ethology, Australia, New Zealand A lamb whose mother has died and which has transferred its attachment to an object, such as a bush or rock, in the locality.

GNU Webster's 1913

1. n. One who places or sets.
2. n. U.S. A deposit of earth, sand, or gravel, containing valuable mineral in particles, especially by the side of a river, or in the bed of a mountain torrent.

WordNet 3.0

1. n. an alluvial deposit that contains particles of some valuable mineral