Prefixes are key morphemes in English vocabulary that begin words. The origin of the prefix *anti-* and its variant *ant-* is an ancient Greek word which meant "against" or "opposite." These prefixes appear in numerous English vocabulary words, such as [*anti*]freeze, [*anti*]dote, [*ant*]onym, and [*ant*]acid. An easy way to remember that the prefix *anti-* means "opposite" or "against" is through the word [*anti*]social, for an [*anti*]social person is the "opposite" of being social, or is "against" being so in her everyday conduct.