An Anglo-Saxon Dictionary is a dictionary of Old English (also known as Anglo-Saxon). Four editions of the dictionary were published. It has often (especially in earlier times) been considered the definitive lexicon for Old English. It is often referred to by the names of its compilers, for example Bosworth or Bosworth & Toller.
This was written by Joseph Bosworth, who in 1858 became the Rawlinsonian Professor of Anglo-Saxon at the University of Oxford: the post was renamed in 1916 as the Rawlinson and Bosworth Professorship of Anglo-Saxon, in Bosworth's honour.
While being attributed to "J. Bosworth & T. N. Toller", this was a revision by Thomas Northcote Toller, based on Bosworth's 1838 dictionary, Bosworth's papers, and additions by Toller.
Thomas Northcote Toller issued a supplement in 1921.
Alistair Campbell issued an edition with "enlarged addenda and corrigenda" in 1972.