spina bifida
    n 1: a not uncommon congenital defect in which a vertebra is
         malformed; unless several vertebrae are affected or there
         is myelomeningocele there are few symptoms; can be
         diagnosed by amniocentesis [syn: spina bifida,
         rachischisis, schistorrhachis]

Spina bifida \Spi"na bif"i*da\ (Med.) [L., cleft spine.]
   A congenital malformation in which the spinal column is cleft
   at its lower portion, and the membranes of the spinal cord
   project as an elastic swelling from the gap thus formed.
   [1913 Webster]