geasa

/G IY1 S AH0/
noun
  1. 1

    A vow or obligation placed upon a person.

  2. 2

    A curse.

  3. 3

    A mystical compulsion.

noun
  1. 1

    A solemn injunction

Source: https://en.wiktionary.org/wiki/geas, https://en.wiktionary.org/wiki/geasa, https://en.wiktionary.org/wiki/geis