Book excerpt: So far, no comprehensive study of the obsolescence of Scandinavian loanwords in English has ever been published. This book remedies that situation, and presents an analysis of the causes of obsolescence of Scandinavian loanwords in English since the 15th century. The study has mainly been based on the Oxford English Dictionary and the Middle English Dictionary. Over 300 loanwords have been selected, grouped into semantic fields and analysed. To account for their disappearance, reasons such as the rivalry of synonyms, the exclusive use in local dialects, the disappearance of the referent as well as rare occurrence or phonological changes were investigated.