tongaid

From Proto-Celtic *tungeti, of complicated etymology.^[1] See the Proto-Celtic page for more.

Additionally, there is no etymological relation between tongaid and as·toing (“to refuse”).

• IPA^(key):

tongaid (conjunct ·toing, verbal noun lugae or luige)

1. to swear (an oath)
   • c. 697-900, Cáin Adomnáin, published in Cáin Adamnáin: an old-Irish treatise on the law of Adamnan (1905, Oxford University Press), edited and with translations by Kuno Meyer, §29

     To·cuitchetar trá huli láechu ⁊ cléircu óg Cána Adomnán do comalnad co brád.

     So, everyone (laymen and clerics included) has sworn to fulfil the Cáin Adomnáin in its entirety forever.

   • c. 800–825, Diarmait, Milan Glosses on the Psalms, published in Thesaurus Palaeohibernicus (reprinted 1987, Dublin Institute for Advanced Studies), edited and with translations by Whitley Stokes and John Strachan, vol. I, pp. 7–483, Ml. 36^a20

     Is maith les a firlugae no·thongad cach fri alaile hi recht ⁊ ní chairigedar.

     He holds in regard the oath that he used to swear to another in law and does not blame it.

   • c. 700–800 Táin Bó Cúailnge, from the Yellow Book of Lecan, published in The Táin Bó Cúailnge from the Yellow Book of Lecan, with variant readings from the Lebor na hUidre (1912, Dublin: Hodges, Figgis, and Co.), edited by John Strachan and James George O'Keeffe, TBC-I 1060

     Abair frisna legi, bíth comardae fora mbuidin, ⁊ toinged a n-imchoimét frim, ⁊ tom·iced bïad cach n-óen-aichde [n-óen-aidche, LU] úaidib.

     Tell the physicians: let there be a token for their group. Let swear the preservation of life to me, and let rations come to me every single night from them.

• Gregory Toner, Sharon Arbuthnot, Máire Ní Mhaonaigh, Marie-Luise Theuerkauf, Dagmar Wodtko, editors (2019), “tongaid”, in eDIL: Electronic Dictionary of the Irish Language