An Etymological Dictionary of Astronomy and Astrophysics

A mathematical rule between two sets which assigns to each element of the first exactly one element of the second, as the expression y = ax^b.

Etymology (EN): From M.Fr. fonction, from O.Fr. function, from L. functio (gen. functionis) “performance, execution,” from functus, p.p. of fungor “to perform, execute.”

Etymology (PE): Karyâ, from Av. kairya- “function;” cf.
Mod.Pers. Laki karyâ “done,” Awromâni kiriyây, kiria “to be done,”
from kar- “to do” (Mod.Pers. kar-, kardan “to do, to make;” Mid.Pers. kardan; O.Pers./Av. kar- “to do, make, build;” Av. kərənaoiti “he makes;” cf. Skt. kr- “to do, to make,” krnoti “he makes, he does,” karoti “he makes, he does,” karma “act, deed;” PIE base k^wer- “to do, to make”)

• -ya suffix of verbal adjectives and nouns (e.g. išya- “desirable,” jivya- “living, fresh,” haiθya- “true,” maidya- “middle,” dadya- “grain”); cf. Skt. kāryá- “work, duty, performance.”