A waltz is a graceful dance where partners glide around the floor in smooth, flowing circles, stepping in a distinctive one-two-three, one-two-three rhythm. The waltz became wildly popular in European ballrooms during the 1800s, and you've probably heard the elegant, swirling music that goes with it: think of the beautiful score from Disney's Beauty and the Beast or Sleeping Beauty.

The dance was considered shocking when it first appeared because partners held each other close while dancing, something that wasn't done in earlier formal dances. But its beauty and romance won people over, and the waltz became the signature dance of grand balls and celebrations.

The word can also mean moving smoothly and confidently through something. When a well-prepared student goes waltzing through a science test, they move through the questions easily and gracefully. If your older sister waltzes into the kitchen and announces she got the lead in the school play, she's entering with confident, happy energy. Sometimes people say someone waltzed right in to describe how they entered a situation with too much confidence or without proper respect for its difficulty.