An interesting instance of a real word losing its meaning and having an erroneous meaning attributed to it. Then, some time later, the correct meaning was uncovered again. Not a word that probably sees much use with either meaning, but an interesting case nonetheless.
abthain, abthane
[An Eng. or rather Lowland Sc. formation on med.L. abthania, for Gaelic Abdhaine, abbacy or abbotrick, abbatia, variously written in the charters Abthen, Abthein, Abbathain, Abbethayne. The meaning of Abthania being lost, it was supposed to be some ancient dignity, for the holder of which the imaginary title of Abthanus was invented by Fordun (Scotochron. IV. xxxix.), and explained by him from a false etymology as Father (abbas) or Superior of the Thanes. Thenceforward the imaginary Abthane flourished in Scottish History, till the recent explanation of the word by Dr. W. F. Skene in Historians of Scotland IV, Fordun II. 413.]
1. Erroneous use: a ‘Superior Thane.’
2. Correct use: an abbacy (of the early Scottish church).
¶If a representative of Gael. abdhaine, abthaine, med.L. abthania, is retained as a special term for ‘the territory of those churches called Monasteria, which were founded by the Columban clergy’ in ancient Celtic Scotland, the best form would be Abthany, as distinct from the equivocal Abthane and his supposed jurisdiction Abthanry or Abthanage.
Neh 