Xenobiotics

Part of speech: noun

Definitions

1. Compounds that are foreign to an organism, often including drugs or pollutants
2. Substances that originate outside a biological system and can impact health and the environment
3. Chemicals not naturally produced within a living organism, frequently involved in research on toxicity and metabolism

Etymology: In ancient Greek, "xenos" meant both "stranger" and "guest," so the same word could describe the foreigner arriving at your door and the host welcoming him. The obligation binding them was "xenia," sacred hospitality, which Greek religion enforced through Zeus Xenios, protector of travelers and guests. Greek "bios" means life, the root behind "biology" and "biography." Joining it to "xeno-" gives a compound meaning roughly "foreign to life," and the ending "-ic" turns it into a term for substances. Used as a noun, it names a chemical that comes from outside a living organism rather than being produced within it.