Source : Webster's Revised Unabridged Dictionary (1913)

Peritropal \Per*it"ro*pal\, a. [Gr. ?, fr. ? to turn around; ?
   around + ? to turn: cf. F. p['e]ritrope.]
   1. Rotatory; circuitous. [R.]

   2. Having the axis of the seed perpendicular to the axis of
      the pericarp to which it is attached.