Definition of rectus in US English:



  • 1Any of several straight muscles.

    • ‘It may also be represented by a single muscle bundle between the lateral and superior recti.’
    • ‘In the kidneys, needles are seen on the inside of the basal membranes of the tubuli recti.’
    • ‘Leading from the seminiferous tubules are the tubuli recti or straight tubules lined only with columnar cells apparently derived from Sertoli cells.’
    • ‘The rectus femoris runs straight down the front of your thigh and, ideally, should protrude farther than any of your other quad muscles.’
    • ‘The rectus femoris, a long muscle that runs straight down the front of the thigh, is one of the major muscles of the quadriceps.’
    1. 1.1 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 forward or sideways.
      • ‘The abdominal muscle responsible for the ‘six-pack’ look is the rectus abdominis.’
      • ‘The most superficial ab muscle, the rectus abdominis, runs from the top of your pubic bone to the sternum.’
      • ‘The main abdominal muscle, the rectus abdominis, is one long muscle that runs from just below the pecs down to the pelvic region.’
      • ‘During expiration, contraction of the rectus abdominis and transversus abdominis muscles draw the pubic plates dorsally, decreasing abdominal volume.’
      • ‘The abdominals include: the rectus abdominis, external and internal obliques, and transverse abdominis.’
    2. 1.2 Any of a number of muscles controlling the movement of the eyeball.
      • ‘Geoff hooked a needle through the rectus, the gossamer-thin muscle that controls eye movement, then immobilized it with a suture.’
      • ‘Editor Ahmed and Ali wondered whether it is the oblique eye muscles or the superior or inferior recti that adduct the eye.’
      • ‘Congenital orbital adherens syndrome was suspected, and MRI of orbits revealed retraction of the right eyeball with shortening of the right medial rectus and left deviation of the nasal septum.’


Early 18th century: from Latin, literally ‘straight’.