The verb to tread means to walk or step on something, especially in a way that matters because of how or where you're walking. When you tread carefully across a frozen pond, you're placing each foot down with thought and caution. When hikers tread along a mountain path, they're walking while paying attention to where they step.

The word often appears in situations where your steps have consequences. You might tread on someone's toes (literally stepping on their foot, or figuratively hurting their feelings). A teacher might warn students not to tread on the newly planted grass. The phrase tread lightly means to proceed with care and awareness, like when you're discussing a sensitive topic with a friend.

Tread is also a noun referring to the grooved surface on a tire or the bottom of a shoe that grips the road or ground. When tire tread wears down, the tire becomes smooth and can't grip as well, making it dangerous to drive on. Winter boots have deep tread to keep you from slipping on ice and snow.

You might also hear the word in tread water, which means to stay afloat in one place by moving your legs and arms, or figuratively, to work hard without making progress.