the symmetrical halves of any the radii, or spheromeres, of a radiate pet, such a starfish.
the shaped halves of any one of the radii, or spheromeres, of a radiate animal, as a starfish.
In biology: A radiated component or organ; one of a set of radiating components arranged such as the spokes of a wheel about a common center; an actinomere: correlated with antimere, metamere, etc. The hands or rays of a starfish arc parameres inside sense.
Either 1 / 2, correct or remaining, of a bilaterally symmetrical animal: today oftener labeled as antimere.
Either one half, correct or left, of one portion or somite of a bilaterally symmetrical animal.