Source : Webster's Revised Unabridged Dictionary (1913)

Octapla \Oc"ta*pla\, n.; etymol. pl., but syntactically sing.
   [NL., fr.Gr. ? (for ? eight) + -pla, as in E. hexapla; cf.Gr.
   ? eightfold.]
   A portion of the Old Testament prepared by Origen in the 3d
   century, containing the Hebrew text and seven Greek versions
   of it, arranged in eight parallel columns.