Oxford Advanced American Dictionary

Definition of wrench noun from the Oxford Advanced Learner's Dictionary

wrench

noun
wrench pronunciation English rentʃ wrench pronunciation American rentʃ
 
1 (especially North American English) (British English usually spanner) [countable] a metal tool with a specially shaped end for holding and turning things, including one which can be adjusted to fit objects of different sizes, also called a monkey wrench or an adjustable spanner2 [singular] pain or unhappiness that you feel when you have to leave a person or place that you loveLeaving home was a terrible wrench for me.3 [countable, usually singular] a sudden and violent twist or pullShe stumbled and gave her ankle a painful wrench.
Idioms

throw a wrench in/into something

(North American English, informal) = throw a monkey wrench in/into something