The Collaborative International Dictionary of English v.0.48:

Sinusoidal \Si`nus*oid"al\, a. (Geom.)
   Of or pertaining to a sinusoid; like a sinusoid.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

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]

WordNet (r) 3.0 (2006):

sinusoidal
    adj 1: having a succession of waves or curves