Definition
To undermine someone's position or chances of success, typically by acting before them or doing something better than them.
When she announced her research findings, a competitor cut the ground from under her feet by publishing similar research first.
He was planning to present the proposal, but the committee cut the ground from under his feet by moving ahead and passing their own.
By publishing his paper first, he cut the ground from under the other researchers, making their findings seem less impactful.