doucai

From to- +‎ Proto-Celtic *unketi, from Proto-Indo-European *h₁unékti, *h₁unkénti (“to get used to, learn”, nasal infix present) from the root *h₁ewk-. Cognate with Sanskrit उच्यति (ucyati, “to be accustomed”), Gothic 𐌱𐌹𐌿𐌷𐍄𐍃 (biuhts, “accustomed”), Old Church Slavonic оучити (učiti, “to teach”) and вꙑкнѫти (vyknǫti, “to acclimate; to learn”), and Lithuanian jùnkti (“get used to”).^[1]

Formerly held to be a specialized sense of do·uic (“has brought”), the perfect of do·beir, and so listed in the Dictionary of the Irish Language; but in fact the two are etymologically unrelated. Nevertheless, the forms of the two may sometimes become conflated, and in some contexts it may be unclear which of the two verbs is intended.

• IPA^(key):

do·ucai (prototonic ·tuccai)

1. to understand

   Synonym: as·gnin

   • 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. 91^c1

     No scrútain-se, in tan no mbíinn isnaib fochaidib, dús in retarscar cairde ṅDǽ ⁊ a remcaissiu, ⁊ ní tucus-sa insin, in ru·etarscar fa naic.

     I used to consider, when I was in the tribulations, whether the covenant of God and his providence had departed, and I didn't understand whether it had departed or not.

• Middle Irish: tuicid
  • Irish: tuig
  • Manx: toig
  • Scottish Gaelic: tuig

• Gregory Toner, Sharon Arbuthnot, Máire Ní Mhaonaigh, Marie-Luise Theuerkauf, Dagmar Wodtko, editors (2019), “do·beir”, in eDIL: Electronic Dictionary of the Irish Language
• Pedersen, Holger (1913) Vergleichende Grammatik der keltischen Sprachen (in German), volume II, Göttingen: Vandenhoeck und Ruprecht, →ISBN, § 665.10, pages 471–472