to cause trouble, especially by spoiling someone's plans.

I don't want to upset the applecart now by asking you to change the date for the meeting.

• put the brakes on something
• put the cart before the horse
• put the cat among the pigeons
• put the clock back
• put the fear of God into
• put the fear of God into someone
• put the finger on
• put the finger on someone
• Put the flags out!
• put the genie back in the bottle
• put the heat on
• put the heat on someone
• put their heads together
• put the kibosh on
• put the kibosh on something
• put the knife in
• put the lid on
• put the lid on something
• put the pedal to the metal
• put the record straight
• put the roses in cheeks
• put the roses in someone's cheeks
• put the screws on
• put the screws on someone
• put the seal on