renaid

Old Irish

From Proto-Celtic *rināti, from Proto-Celtic *h₂ri-né-H-ti, from Proto-Indo-European *h₂reyH- (“to count”).^[1]^[2] Cognate with Ancient Greek ἀριθμός (arithmós, “number”), νήριτος (nḗritos, “countless”); Latin rītus (“religious observances”); Old English rīm (“calculation”); Tocharian B yärm (“measure”).

renaid (conjunct ·ren, verbal noun reicc)

to sell, to exchange, to barter
- c. 800, Würzburg Glosses on the Pauline Epistles, published in Thesaurus Palaeohibernicus (reprinted 1987, Dublin Institute for Advanced Studies), edited and with translations by Whitley Stokes and John Strachan, vol. I, pp. 499–712, Wb. 28^c2
  Ní rïat na dánu díadi ara n-indeb domunde.
  Let them not sell the divine gifts for the worldly wealth.

Simple, class B IV present, reduplicated preterite, i future, a subjunctive

⇒ Middle Irish: reccaid (denominative from verbal noun)
- Irish: reic
- Scottish Gaelic: reic

Old Irish mutation
Radical	Lenition	Nasalization
renaid also rrenaid after a proclitic ending in a vowel	renaid pronounced with /r(ʲ)-/	unchanged
Note: Some of these forms may be hypothetical. Not every possible mutated form of every word actually occurs.

^ Schumacher, Stefan, Schulze-Thulin, Britta (2004) “*ri-na-”, in Die keltischen Primärverben: ein vergleichendes, etymologisches und morphologisches Lexikon [The Celtic Primary Verbs: A comparative, etymological and morphological lexicon] (Innsbrucker Beiträge zur Sprachwissenschaft; 110) (in German), Innsbruck: Institut für Sprachen und Literaturen der Universität Innsbruck, →ISBN, page 551
^ Kümmel, Martin Joachim (2011–2023) “*h₂rei̯H-”, in Addenda und Corrigenda zu LIV²‎^[1], page 38