It is important to recognize that a human language such as English is a social phenomenon which is at the mercy of its users and which may change over time and vary from region to region where it is spoken. The recognition of these dimensions of variation will come in useful in the discussion of synonymy below, but these are also matters of great practical importance for the language learner. Regional variation may be a question of differences between local or regional dialects within one country, such as the difference between the Northern and West Midland dialects in England, or it may be a question of differences between standardized major varieties of English, such as American English and British English. In our study of the meaning of words we can focus on the ways in which the senses of two or more lexemes are related to each other.
Synonyms are different lexemes with the same sense.
Given this kind of definition we can say that GIRL and LASS are synonyms, since both have the sense 'young female human being'. A more restrictive definition of synonymy would require that two synonyms are completely interchangeable in every possible context. This kind of definition makes synonymy a rare phenomenon indeed. Similarly, the verbs denoting various kinds of human motion presented in lecture 4 can also be regarded as near-synonyms. Two lexemes are antonyms when they represent the opposite ends of some sense dimension.