we had the perfect plan for today, but when the homeless man slashed my van's tires, he threw a wrench in the system
a problem that makes a flawless plan or machine go wrong, as though one were throwing a wrench inbetween a perfectly set pair of gears
"we had the perfect plan for today, but when the homeless man slashed my van's tires, he threw a wrench in the system" What is the definition of "a wrench in the system"?