First published in 1874, this landmark dictionary of old Icelandic is both authoritative and comprehensive. It offers thousands of illustrative quotations, full descriptions of pronunciation for every letter, and a detailed outline of grammar that includes the old Icelandic alphabet, word formation, and spelling. The 52-page supplement contains a list of additional words and references from the eleventh century to the mid-fourteenth century.

An essential point of reference for any student of old Icelandic, supplement author Sir William A. Craigie stated in 1957 that 'though the dictionary is mainly intended for the old authors, both in prose and poetry, it endeavours to embrace an account of the whole language, old and new'.