concomitant (adj.)

"a being together or in connection with another," 1530s, from French concomitance or directly from Medieval Latin concomitantia, from Late Latin concomitantem (see concomitant). In theology, "the coexistence of the blood and body of Christ in the bread of the Eucharist." Related: Concomitancy.

word-forming element usually meaning "with, together," from Latin com, archaic form of classical Latin cum "together, together with, in combination," from PIE *kom- "beside, near, by, with" (compare Old English ge-, German ge-). The prefix in Latin sometimes was used as an intensive.

Before vowels and aspirates, it is reduced to co-; before -g-, it is assimilated to cog- or con-; before -l-, assimilated to col-; before -r-, assimilated to cor-; before -c-, -d-, -j-, -n-, -q-, -s-, -t-, and -v-, it is assimilated to con-, which was so frequent that it often was used as the normal form.