AMBI means "on both sides" or "around"; ambi- comes form Latin. Most of us are either right-handed or left-handed, but ambidextrous people can use their right and left hand equally well.

EPI is a Greek prefix that may mean various things, but usually "on, over" or "attached to." So an earthquake's epiccenter is the ground right over the center of the quake. And your epidermis is the outer layer of your skin, on top of the inner dermis.

HYP/HYPO is a Greek prefix meaning "below, under." Many hypo- words are medical. A hypodermic needle injects medication under the skin. Hypotension, or low blood pressure, can be just as unhealthy as the better-known hypertension, or high blood pressure.

THERM/THERMO comes from the Greek word meaning "warm." A thermometer measures the amount of warmth in body, the air, or an oven. A thermostat makes sure the temperature stays at the same level. And it's easy to see why the German manufacturers of a vacuum-insulated bottle back in 1904 gave it the name Thermos.

POLY comes from polys, the Greek word for "many." A polytechnic institute offers instruction in many technical fields. Polygamy is marriage in which one has many spouses, or at least more than the legal limit of one. And Polysyllabic words are words of many syllables--of which there are quite a few in this book.

PRIM comes from primus, the Latin word for "first." Something primary is first in time, rank, or importance. Something primitive is in its first stage of development. And something primeval had its origin in the first period of world or human history.

HOM/HOMO comes from homos, the Greek word for "same," which in English words may also mean "similar." A homograph is a word spelled like another word but different in meaning or pronunciation, and a homosexual is a person who favors others of the same sex. (This root has nothing to do with the Latin homo, meaning "person," as in Homo sapiens, the French homme, and the Spanish hombre.)

DIS comes from Latin, where it means "apart." In English, its meanings have increased to include "opposite" or "not" (as in distaste, disagreeable), "deprive of" (disinfect), or "exclude or expel from" (disbar). The original meaning can still be seen in a word like dissipate, which means "to break up and scatter."

Latin Borrowings