TERM/TERMIN comes from the Latin verb terminare, "to limit, bound, or set limits to," and the noun terminus, "limit or boundary." In English, those boundaries or limits tend to be final. A term goes on for a given amount of time and then ends, and to terminate a sentence or a meeting or a ballgame means to end it.

GEO comes from the Greek word for "Earth." Geography is the science that deals with features of the Earth's surface. Geologists study rocks and soil to learn about the Earth's history and resources. Geometry was originally about measuring portions of the Earth's surface, probably originally in order to determine where the boundaries of Egyptians' farms lay after the annual flooding by the Nile River.

SPHER comes from the Greek word for "ball." A ball is itself a sphere, as is the ball that we call Earth. So is the atmosphere, and so are several other invisible "spheres" that encircle the Earth.

VERT comes from the Latin verb vertere, meaning "to turn" or "to turn around." Vertigo is the dizziness that makes it seem as if everything is turning around you. And an advertisement turns your attention to a product or service.

MORPH comes from the Greek word for "shape." Morph is itself an English word with a brand-new meaning, which was needed when we began to digitally alter photographic images or shapes to make them move or transform themselves in often astonishing ways.

FORM is the Latin root meaning "shape" or "form." When you march in formation, you're moving in ordered patterns. And a formula is a standard form for expressing information, such as a rule written in mathematical symbols, or the "Sincerely yours" that often ends a letter.

DOC/DOCT comes from the Latin docere, which means "to teach." So, for instance, a doctor was originally a highly educated person capable of instrcuting others in a field--which usually wasn't medicine.

TUT/TUI comes from a Latin verb meaning "to look after," and in English the root generally shows up in words that include the meaning "guide," "guard," or "teach"--such as tutor, the name for a private teacher who guides a student (or tutee) through a subject.

Number Words

DI/DUP Greek and Latin prefixes meaning "two," shows up in both technical and nontechnical terms, wich dup- sometimes shortened to du-. So a duel is a battle between two people. A duet is music for a duo, or pair of musicians. A duplicate is an exact copy, or twin. And if you have dual citizenship, you belong to two countries at once.

BI/BIN also means "two" or "double." A bicycle has two wheels, and binoculars consist of two little telescopes. Bigamy is marriage to two people at once. And a road built through the middle of a neighborhood bisects it into two pieces.