monkey wrench: Meaning and Definition of

mon'key wrench"

1. Also called,a wrench having an adjustable jaw permitting it to grasp nuts or the like of different sizes.
2. something that interferes with functioning; obstacle: He threw a monkey wrench into our plans.

mon•key-wrench

1. to prevent, delay, or sabotage industrialization or development of wilderness areas, esp. through vandalism.