Definition of a wrench in (the works) in US English:

a wrench in (the works)

phrase

  • A person or thing that prevents the successful implementation of a plan.

    ‘he has thrown a wrench in the works by saying he would prefer direct elections to happen’
    ‘his injury has put a wrench in those plans’
    interfere, interfere with, hinder, hamper, obstruct, disrupt, impede, inhibit, retard, baulk, thwart, foil, curb, delay, set back, slow down, hold back, hold up
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