promiscuous (adj.)

c. 1600, people or things, "mingled confusedly, grouped together without order, consisting of a disorderly mix; indiscriminate," from Latin promiscuus "mixed, indiscriminate, in common, without distinction," from pro "forward" (see pro-) + miscere "to mix" (from PIE root *meik- "to mix"). Meaning "indiscriminate in sexual relations" recorded by 1857, from promiscuity. The Latin adjective was used with conubia (such as between patricians and plebeians). Related: Promiscuously.