Abstract:
The study aims to investigate word classes, functions and contexts of the word /bon/ in Thai, along with its meanings and concepts as well as processes and mechanisms of semantic change and development from Sukhothai period to the reign of King Rama IX of Rattanakosin period (2016 A.D.), using cognitive semantics, grammaticalization, and lexicalization as conceptual frameworks. There were 2,441 tokens of the word /bon/ in total, according to this study. It was found that, firstly, the word /bon/ occurred in various distributions, functioning as a head, a modifier, a connector, and a complement. In connection with word classes, it was identified as a noun, an adjective, a preposition, and an adverb. Next, the meanings of the word /bon/ can be classified into two groups. The first group denoted spatial concepts including an area higher or above a reference level and higher or more powerful status. The rest denoted three spatial relations between an entity and another including an entity higher than or above another, an entity inside another, and an entity beside/against but supported by another entity. Then, the semantic change of the word /bon/ involved metaphor, metonymy, grammaticalization, and lexicalization. In addition, the mechanisms involved in grammaticalization were metaphorical extension, semantic bleaching, persistence, reanalysis, and inference. Finally, the meaning development of the word /bon/ also exhibited the change from a concrete meaning to an abstract one.