semicircular
    adj 1: curved into a half circle

Semicircular \Sem`i*cir"cu*lar\, a.
   Having the form of half of a circle. --Addison.
   [1913 Webster]

   Semicircular canals (Anat.), certain canals of the inner
      ear. See under Ear.
      [1913 Webster]

curved \curved\ adj.
   1. not straight; having or marked by curves. Opposite of
      straight.

   Note: [Narrower terms: arced, arched, arching, arciform,
         arcuate, bowed; falcate, sickle-shaped; flexuous;
         incurvate, incurved: recurved, recurvate;
         semicircular: serpentine, snaky: sinuate, sinuous,
         wavy: sinusoidal]

   Syn: curving.
        [WordNet 1.5]

   2. (Botany) curved with the micropyle near the base almost
      touching its stalk; -- of a plant ovule. Opposite of
      orthotropous.

   Syn: campylotropous.
        [WordNet 1.5]