Placer

From place + -er("suffix forming agent noun").

Full definition of placer

(plural placers)

One who places or arranges something.
(slang) One who deals in stolen goods; a fence.2011, Jonathon Green, Crooked Talk: Five Hundred Years of the Language of Crime, %22placers%22+stolen+-intitle:%22%22+-inauthor:%22%22&hl=en&sa=X&ei=tVTcT_nmCqaZiAe1qaS8Cg&redir_esc=y#v=onepage&q=%22placer%22|%22placers%22%20stolen%20-intitle%3A%22%22%20-inauthor%3A%22%22&f=false page 104â€” The 20th-century buyer is self-explanatory, while the placer is a middle-man who places stolen goods with a purchaser.

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

(plural placers)

(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.

1951, Josiah Macy, Jr. Foundation, Problems of Infancy and Childhood, Volume 4, %22placers%22+lamb+-intitle:%22%22+-inauthor:%22%22&dq=%22placer%22|%22placers%22+lamb+-intitle:%22%22+-inauthor:%22%22&hl=en&sa=X&ei=kx_cT6T3MsG3iQfevJTACg&redir_esc=y page 101,This is a â€œplacerâ€ 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 motherâ€²s body....
1971, American Society of Animal Science. Journal of Animal Science, Volume 32, Pages 601-1298, %22placer+lambs%22+-intitle:%22%22+-inauthor:%22%22&dq=%22placer+lamb%22|%22placer+lambs%22+-intitle:%22%22+-inauthor:%22%22&hl=en&sa=X&ei=n1HcT5DsFYafiQfK1NmYCg&redir_esc=y page 1281,In Australia â€œplacerâ€ lambs are also destroyed, for these too are of little use; they will return constantly to one place, not staying with the flock.

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

(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

1995, Paul T. Craddock, Early Metal Mining and Production, page 110: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.
2002, Philip Ball, The Elements: A Very Short Introduction, Oxford 2004, p. 46: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.
2008, Tanyo Ravicz, Of Knives and Men, Alaskans, %22placers%22+lamb+-intitle:%22%22+-inauthor:%22%22&hl=en&sa=X&ei=kx_cT6T3MsG3iQfevJTACg&redir_esc=y#v=onepage&q=%22placer%22|%22placers%22%20lamb%20-intitle%3A%22%22%20-inauthor%3A%22%22&f=false page 77,He still ran a placer mine in the Interior.