to make something inoperable; to ruin someone's plans. (Informal.)
Please, Bill, be careful and don't gum up the works.Tom sure gummed it up.Tom sure gummed up the whole plan.
Idiom
gum up the works
to prevent a machine or system from operating correctly.
In bad weather, twice as many people use their cars on the road, which really gums up the works.
gum up the works
To interfere with the proper functioning of something. More regulations will just gum up the works.
gum up the works
If something gums up the works, it makes it difficult for a process or activity to happen. We hope to use the new electronic voting machines, but legal challenges could still gum up the works.
gum up the ˈworks
(informal) make progress or an activity impossible: The building was going well, but the delay in delivering more bricks has really gummed up the works.