Euphemisms constitute a universal linguistic phenomenon present across all known languages and cultures, serving as essential communicative tools that facilitate social interaction while maintaining politeness and avoiding offense. This article examines the theoretical foundations of euphemisms, exploring their origins, definitions, primary functions, and linguistic features. Drawing on interdisciplinary perspectives from linguistics, cognitive science, and sociolinguistics, the study demonstrates that euphemisms are not merely stylistic alternatives but complex linguistic mechanisms deeply embedded in cultural values and social norms. The article analyzes the classification systems proposed by various scholars, discusses the phonetic, lexical, grammatical, and rhetorical devices employed in euphemism formation, and explores the dynamic nature of euphemistic expressions through the concept of the "euphemism treadmill." By establishing a comprehensive theoretical framework, this article lays the groundwork for comparative cross-linguistic analysis of euphemistic phraseological units in English and Uzbek languages