The hardest thing about being a circus acrobat might be wearing a unitard — the skin-tight, stretchy combination of a leotard and tights.
Many athletes and performers wear unitards, which sometimes have built-in tight shorts and sometimes extend to the ankles like footless tights. A unitard is intended to fully cover the wearer's body while still allowing for complete flexibility — it's ideal for contortionists and gymnasts. The word itself comes from leotard, which was named for Jules Léotard, an 1880s French trapeze artist. Unitard has the prefix uni, "having one only," because it's a complete one-piece outfit.