Words for thirty and related things in Celtic languages.
| Proto-Celtic | *trīkontes = thirty |
|---|---|
| Gaulish | tricontis = thirty |
| Old Irish (Goídelc) | trícha [ˈtʲrʲiːxo] = thirty tríchatmad = thirtieth tríchtaige = thirty day period |
| Middle Irish (Gaoidhealg) | trícha, triúcha, tricha, triocha, tricho = thirty tríchatmad, trichatmad, trichadmadh = thirtieth tríchtaige, trichtaigi = period of 30 days/years, etc tríchtach, tríteach = thirty-fold, consisting of 30 trícha cét = a military force, political or terrirtorial unit; of force of fighting men, cantred, barony (lit. ‘300’) |
| Irish (Gaeilge) | tríocha = thirty tríochadú = thirtieth na tríochaidí = the thirties tríocha céad = large territorial division, barony |
| Scottish Gaelic (Gàidhlig) | trichead [triçəd] = thirty tritheadamh (30ᵐʰ) = thirtieth (30ᵗʰ) na tritheadan = the thirties |
| Manx (Gaelg) | treead = thirty |
| Proto-Brythonic | *trigont = thirty |
| Old Breton | tricont, trigont = thirty |
| Middle Breton (Brezonec) | tregont = thirty tregontad = about thirty tregontet, tregontvedenn, tregontvet = thirtieth tregontkementiñ, tregontvedenniñ = to multiply by thirty tregontvloaziad = a period of 30 years |
| Breton (Brezhoneg) | tregont [ˈtreːɡɔ̃n(t)] = thirty tregontved = thirtieth tregontvedenn = thirtieth part tragontad = around thirty |
Etymology: from Proto-Indo-European *tridḱómt (thirty) from *tri- (three) and *déḱm̥ (ten) [source].
Words from the same roots include thirty in English, tridhjetë (thirty) in Albanian, երեսուն [jɛɾɛˈsun] (thirty) in Armenian, trenta (thirty) in Italian and trente (thirty) in French, and words for thirty in other Indo-European languages [source].
Thirty is also trideg (three-ten) in Welsh in the decimal version of the numbers. For other words for thirty, see the post about words for ten, as thirty is 10 on 20 in the vigesimal system.
Sources: Wiktionary, Am Faclair Beag, Online Manx Dictionary, Teanglann.ie, eDIL – Electronic Dictionary of the Irish Language, In Dúil Bélrai English – Old Irish glossary, Geiriadur Prifysgol Cymru, Gerlyver Kernewek, Gerlyvyr Cernewec, Dictionaire Favereau, TermOfis, Le dictionnaire diachronique du breton, Geriafurch, English – ProtoCeltic WordList (PDF), Etymological Dictionary Of Proto Celtic