koeffisient.

From Latin coefficiēns (“coefficient”), from coefficio, from both co-, from con-, from cum (“(along) with, at”), from Old Latin com, from Proto-Italic *kom (“with, along, at”), from Proto-Indo-European *ḱóm (“next to, at, with, along”), perhaps from *ḱe (deictic particle) + and from efficio (“to make, work out, effect”), from both ex- (“out, away”), from ē, ex (“out, from”), from Proto-Indo-European *h₁eǵʰs (“out”) + and from faciō (“to do, make”), from Proto-Italic *fakjō (“to make”), from earlier *θakjō, from Proto-Indo-European *dʰh₁k-yé-ti, from *dʰeh₁- (“to do, put, place”).