Lexicology is a branch of linguistics, which studies the vocabulary of a language. Its basic task is to study the origin, the different properties of the vocabulary of a language. In other words, lexicology is concerned with words and set phrases which function in speech. Lexicology also studies all kinds of semantic relations (synonyms, antonyms etc) and semantic grouping (semantic fields). Etymologically the word «lexicology» is a Greek word: