6.1 The study of meaning 6.2 Reference and sense 6.2.1 Reference 6.2.2 Sense 6.3 Classification of lexical meanings 6.3.1 Referential meaning and associative meaning 6.3.2 Types of associative meaning 6.4 Lexical sense relations 6.4.1 Synonymy 6.4.2 Antonymy 6.4.3 Homonymy 6.4.4 Polysemy 6.4.5 Hyponymy 6.4.6 Meronymy