ambi, amphi [both]

ambidextrous (skilled with both hands)

amphibious (living on both land and water)

anti [against]

antifreeze (a liquid that works against freezing)

antipollutant (designed to work against pollution)

astro [star]

astronaut (star or space traveler)

astronomy (study of the stars)

auto [self]

autobiography (writing about yourself)

autonomy (self-government)

bi, bin [two]

binocular (using both eyes)

biweekly (every two weeks)

circum [around]

circumference (the line that goes around a circle)

circumnavigate (to travel completely around)