|3.||informal (US), (Canadian) to extort from|
|4.||(Austral) (also intr) to dig for (opal)|
|5.||a type of chisel with a blade that has a concavo-convex section|
|6.||a mark or groove made with, or as if with, a gouge|
|7.||geology a fine deposit of rock fragments, esp clay, occurring between the walls of a fault or mineral vein|
|8.||informal (US), (Canadian) extortion; swindling|
|[C15: from French, from Late Latin gulbia a chisel, of Celtic origin]|
A strong curved chisel used in bone surgery.