rectus
/ˈrektəs/noun
(pl. recti)
1- Anatomy any of several straight muscles, in particular【剖】直肌, 尤指：
1.1
- （亦作rectus abdominis /æbˈdɒmɪnɪs/）each of a pair of long flat muscles at the front of the abdomen, joining the sternum to the pubis and acting to bend the whole body forwards or sideways腹部直肌。
1.2
- any of a number of muscles controlling the movement of the eyeball眼部直肌。
词源
early 18th cent.: from Latin, literally 'straight'.