Abbreviated form of Ces Noínden Ulad [nine days' debility/pangs of the Ulstermen]. When Crunniuc mac Agnomain forces his wife Macha (3) to run a humiliating foot-race with a horse, she curses the watching Ulstermen so that they will suffer the pain of giving birth, at times of their greatest difficulties, for nine times nine generations. Also known as ceisnoidhe / ces noínden Ulad [nine days' affliction]. The episode is retold at the beginning of the Táin Bó Cuailnge [Cattle Raid of Cooley]. Noínden Ulad may be an Irish instance of what anthropologists call couvade, the practice in many pre-technological societies in which the husband of a woman in labour takes to his bed as if he were bearing the child.
See Vernam E. Hull (ed.), ‘Noínden Ulad: The Debility of the Ulidians’, Celtica, 8 (1968), 1–42; Vernam E. Hull (ed.), ‘Ces Ulad: The Affliction of the Ulstermen’, Zeitschrift für celtische Philologie, 29 (1962/4), 305–14; Tomás Ó Broin, ‘What is the “Debility” of the Ulstermen?’, Éigse, 10(4) (1961/3), 286–99; ‘The Word Noínden’, Éigse, 13 (1969/70), 165–76.