placer

Etymology 1

From place + -er (agent noun suffix).

noun

1. One who places or arranges something.
2. (slang) One who deals in stolen goods; a fence.
3. (gambling, in combination) A horse, etc. that finishes in a particular place in a race.
   a third-placer

Etymology 2

From place + -er (suffix apparently denoting association).

noun

1. (ethology, sheep, 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.
   This is a “placer” sheep, as it is called. The prerequisites to this condition are that the young sheep must be still nursing, but must have begun to nibble grass. It must be the young of a mother that has been somewhat isolated, away from the corral and away from the herd, by herself out on the prairie. Now, when the mother dies, the lamb remains close to the mother′s body[…]. 1951, Josiah Macy, Jr. Foundation, Problems of Infancy and Childhood, volume 4, page 101
   1971, American Society of Animal Science. Journal of Animal Science, Volume 32, Pages 601-1298, page 1281, In Australia “placer” lambs are also destroyed, for these too are of little use; they will return constantly to one place, not staying with the flock.

Etymology 3

From American Spanish placer, from earlier placel, apparently from obsolete Portuguese placel.

adj

1. (mining) alluvial; occurring in a deposit of sand or earth on a river-bed or bank, particularly with reference to precious metals such as gold or silver
   Placer gold comes from the weathering of the primary veins releasing the gold to be transported by water action and concentrated in gravel or sand beds. 1995, Paul T. Craddock, Early Metal Mining and Production, page 110
   Since time immemorial, people found that they could extract the gold from placer deposits by sifting the fine-grained material through a mesh: the technique of panning. 2002, Philip Ball, The Elements: A Very Short Introduction, Oxford, published 2004, page 46
   He still ran a placer mine in the Interior. 2008, Tanyo Ravicz, Of Knives and Men: Alaskans, page 77

noun

1. A place where the superficial detritus is washed for gold, etc.
2. (by extension) Any place holding treasures.