The term antonymy is used for oppositeness of meaning; words that are opposite in meaning are antonyms. Oppositeness can be found on different dimensions and different kinds of antonyms have been found.

Some antonyms are gradable because there are often intermediate forms between the two members of a pair. So it is a matter of degree. For example, old and young are immediately recognized as antonyms, but they stand for two extremes, between which there exist intermediate forms representing differing degrees of being old or young, such as “middle-aged, mature, elderly”. “Good” and “bad” is also a pair of gradable antonyms. A pair of complementary antonyms is characterized by the feature that the denial of one member of the pair implies the assertion of the other. In other words, it is not a matter of degree between two extremes, but a matter of either one or the other. For example, a person can be either “alive” or “dead”, either “male” or “female”; there is no third possibility. Therefore, “alive” and “dead” is a pair of complementary antonyms and so is “male” and “female”. Pairs of words that exhibit the reversal of a relationship between the two items are called relational opposites. For example, if A is the husband of B, then B is the wife of A. So “husband” and “wife” is a pair of relational opposites; so are teacher and student.