Affixes

A polyglot (Greek glōtta, tongue) is a person who knows or uses several languages; a polymath (Greek manthanein, learn) is a person of wide-ranging knowledge or learning; a polygon (Greek ‑gōnos, -angled) is a plane figure with at least three straight sides and angles, and typically five or more; polygamy (Greek gamos, marriage) is the practice or custom of having more than one wife or husband at the same time; polyphonic (Greek phōnē, voice, sound) refers to producing many sounds simultaneously.

In chemistry, a polymer (Greek meros, a share) is a substance whose molecular structure has been built up from a large number of similar units bonded together; poly‑ appears in a large number of terms for chemical compounds of this sort, including most substances generically called plastics: polythene or polyethylene, chiefly used for plastic bags, food containers, and other packaging; polycarbonate, a tough material often used as housings for consumer products; polytetrafluoroethylene or PTFE, used for the coating on non-stick saucepans and the like; polyester, used chiefly to make synthetic textile fibres. The polychlorinated biphenyls, PCBs, are a group of very stable but toxic compounds that are persistent in the environment; polystyrene is a polymer of styrene, used chiefly as lightweight rigid foams and films; a substance that is polyunsaturated, such as a fat or oil, contains several double or triple bonds between carbon atoms.