0 a tool with parts that can be moved to tighten or unfasten any size of nut and bolt --
1 a tool that can be adjusted to hold or turn nuts and bolts (= metal fasteners that screw together) of different widths --
Monkey wrenches are another type of adjustable spanner with a long history; the origin of the name is unclear.
He throws a monkey wrench into the machine, destroying it.
Bugs then rouses himself and chases the gremlin who still has the monkey wrench, only to get clobbered on the head with it.
Bugs recovers and gives chase only to be clobbered on the head by the gremlin with the monkey wrench, causing him to faint.
However, such an event was not to be complete without a monkey wrench thrown in.
We do not intend to put a monkey wrench in the machinery, but we shall do our best to support them.
Somebody has thrown a monkey wrench into the works and the feeling here is that the utmost is not being done.
And some service stations started to sell other goods besides car spares - a practice that a contemporary journalist christened 'monkey wrench merchandising'.