Antonomasia is a significant rhetorical and lexical-semantic device in the English language, involving the substitution of a proper name for a common noun or vice versa. This paper investigates the lexical-semantic characteristics of antonomasia in English, examining its structural patterns, semantic mechanisms, and functional roles in literary, journalistic, and everyday discourse. The study employs a descriptive-analytical approach combined with contextual and semantic analysis of selected examples drawn from literary texts and contemporary media. The findings reveal that antonomasia operates through metonymic and metaphoric processes, contributing to semantic enrichment, stylistic expressiveness, and cultural coding in English. The study underscores the importance of antonomasia as a productive word-formation and meaning-transfer mechanism in the English lexical system.