Geas

A geis or geas (pl. geasa) is an idiosyncratic taboo, whether of obligation or prohibition, similar to being under a vow or curse, yet the observance of which can also bring power and blessings. It is also used to mean specifically a spell prohibiting some action. Geasa are common in Irish and Scottish folklore and mythology, as well as in modern English-language fantasy fiction.[1]

The word originates in Old Irish, also known as Old Gaelic, and retains the same form in Modern Irish (nominative singular geis /ɟɛʃ/, nom. plural geasa /ˈɟasˠə/; genitive sg. geise /ˈɟɛʃə/, gen. pl. geas /ɟasˠ/). In modern Scottish Gaelic, the spelling has evolved in a slightly different direction (nom. sg. geas /kʲes/, nom. pl. geasan, gen. sg. geis or geasa). It has also been borrowed into English in both forms (sg. geas or geis /ɡɛʃ/ or /ˈɡi.əʃ/, pl. geasa)).

  1. ^ Michael Quinion, World Wide Words (accessed 8 November 2010)