1. n. []

Anything in the wellbore that is not supposed to be there. The term is usually reserved for small pieces of steel such as hand tools, small parts, bit nozzles, pieces of bits or other downhole tools, and remnants of milling operations.

See: bridge,  fish,  junk basket,  junk basket,  mechanical sticking,  mill,  rathole,  reverse circulation,  sidetrack