This book explores the semantics and pragmatics of honorifics, expressions that indicate the degree of formality that a speaker feels is required in interacting with another person. Although these expressions are found in many languages worldwide, this volume is the first to approach the area from the perspective of formal semantics and pragmatics. Elin McCready treats honorifics - and expressions with honorific import - as carriers of expressive content that contributes either directly or indirectly to a register corresponding to the current formality of the speech situation. The analysis is applied to a variety of empirical examples, including utterance and argument honorifics in Japanese, Thai, and several other languages. It is proposed that the distinct strategies that different languages use for honorification have implications for the grammaticality of certain combination of honorifics. The volume also explores the connections between honorification and a range of theoretical issues in social meaning and the expression of gender. It will hence appeal not only to researchers in formal semantics and pragmatics, but also to sociolinguists, anthropological linguists, and philosophers.