Bipedalism is the characteristic of walking on two feet, rather than four. Your bipedalism means you stand upright on two legs — it also means that you skip, run, dance, and tiptoe using two feet.
This word's roots go back to the Latin bi-, "two," and ped, "foot." Bipedalism is any kind of movement involving two feet, and animals that get around this way are described as bipedal or called bipeds. As human ancestors evolved, bipedalism became a big advantage, allowing us to grab things with our hands as we stood and walked around on our feet. Other animals that use bipedalism include ostriches, bears, and some apes.