An Etymological Dictionary of Astronomy and Astrophysics

Math.: The quotient of two quantities arrived at by dividing one by the other.

Etymology (EN): From L. ratio “reckoning, calculation,” also “reason,” from rat-, p.p. stem of reri “to reckon, calculate,” also “think,” → reason.

Fr. rapport, back-formation from rapporter “bring back,” from → re- “back, again” + apporter “to bring,” from L. apportare “to bring,” from → ad- “to” + portare “to carry.”

Etymology (PE): Vâbar, on the model of Fr. rapport “bringing back,” as above, from vâ-
prefix meaning “back to the original place, again,” → re-,

• bar present stem of bordan “to carry, lead” (Mid.Pers. burdan,
  O.Pers./Av. bar- “to bear, carry,” barəθre “to bear (infinitive),” Skt. bharati “he carries,” Gk. pherein, L. fero “to carry;” PIE base *bher- “to carry”).