English

Verb

throw a spanner in the works ‎(third-person singular simple present throws a spanner in the works, present participle throwing a spanner in the works, simple past threw a spanner in the works, past participle thrown a spanner in the works)

1. (idiomatic, Britain) To introduce a problem, dilemma or obstacle, something unexpected or troublesome.

   Half way through the production of Macbeth, the director found that the stage was smaller than he expected. This really threw a spanner in the works.

See also

• monkey wrench (US)