An Etymological Dictionary of Astronomy and Astrophysics

1. To change units of one measuring or calculating system into units of another.
   
2. To transform from one material or state to another.

Etymology (EN): M.E. converten, O.Fr. convertir, from L. convertere “to turn around, transform,” from → com- “together” + vertere “to turn;” cognate with Mod.Pers. gardidan “to change, to turn,”
→ conversion.

Etymology (PE): Compound verb from hâgard, → conversion, + kardan “to do, to make,” → -ize.