直ちょく立りつ歩ほ行こう

noun, noun or participle which takes 'suru'

walking upright; bipedal locomotion

Refers to the act of walking on two legs in an upright posture, often used in contexts of human evolution or robotics.

• 人じん類るいは直ちょく立りつ歩ほ行こうを始はじめたことで手てを自じ由ゆうに使つかえるようになった。

  Humans became able to use their hands freely by starting to walk upright.