Doctor

Words for doctor in Celtic languages.

Irish (Gaeilge) dochtúir [d̪ˠɔxˈt̪ˠuːɾʲ / ˈd̪ˠʌxt̪ˠuɾʲ] = doctor
Scottish Gaelic (Gàidhlig) dotair [dɔhdɛrʲ] = doctor, surgeon, physician
Manx (Gaelg) doghtoor = doctor

Etymology: from the Latin doctor (teacher, instructor), from doceō (teach), from the Proto-Italic *dokeō (tell, inform, teach, instruct), from the Proto-Indo-European *deḱ- (to take) [source].

Sources: Wiktionary, Am Faclair Beag, teanglann.ie, Dictionary of the Irish Language On-Line Manx Dictionary

Proto-Celtic *lī(φ)agi- = doctor
Old Irish (Goídelc) líaig = leech, doctor, physician
Irish (Gaeilge) lia = healer, physician
Scottish Gaelic (Gàidhlig) lèigh [ʎeː] = physician, surgeon
lighiche [ʎi.ɪçə] = healer, physician, surgeon
Manx (Gaelg) (fer/ben) lhee = (male/female) doctor, physician

Etymology: from the Proto-Indo-European lēg(‘)- (doctor), the same root as the English word leech [source].

Sources: Wiktionary, Proto-Celtic English Word List, Am Faclair Beag, teanglann.ie, Dictionary of the Irish Language On-Line Manx Dictionary

Proto=Brythonic *meðïg = doctor
Welsh (Cymraeg) meddyg [ˈmɛðɪɡ / ˈmeːðɪɡ] = doctor
Cornish (Kernewek) medhek [mɛðɛk / ‘mɛðɐk] = doctor, physician
Breton (Brezhoneg) mezeg = doctor

Doctor

Etymology: from the Latin medicus (doctor), from medeor (I heal, cure, remedy), from the Proto-Italic *medēōr (to heal), from the Proto-Indo-European *med- (to measure, give advice, heal) [source].

Words marked with a * are reconstructions.

Sources: Wiktionary, Geiriadur Prifysgol Cymru, Gerlyver Kernewek, Dictionnaire Favereau

To Write

Words for writing, script and related things in Celtic languages:

Illuminated manuscript

Old Irish (Goídelc) scríbaid [ˈsʲkʲrʲiːviðʲ] = to write (down), compose
Middle Irish (Gaoidhealg) scríbaid = to write (down), compose
aithscríbaid = rewrites
scríbend = the act of writing
Irish (Gaeilge) scriobh [ʃcɾʲiːvˠ / ʃcɾʲiːw] = to write, fill in, compose; (hand)writing
scriobhaí = scribe, amanuensis
scríobhneóir = writer, author
scríobhneóireacht = writing, penmanship, literary work
scríofa = written
Scottish Gaelic (Gàidhlig) sgrìobh [sgrʲiːv] = to write, compose, inscribe
sgrìobhadh [sgrʲiːvəɣ] = writing, composing, inscribing, inscription, penmanship, writings, works
sgrìobhaiche = scribe, correspondent, writer
sgrìobhair = writer, scribe
Manx (Gaelg) screeu = document, writing; to inscribe, pen, scribe, write
screeuee = of writing
screeudeyr = scribe, secretary, secretary bird, writer
scrudeyr = scribe, secretary
screeudeyrys = writing
screeuit, screeut, scruit = written
Proto-Brythonic *skriβenn = writing, something written
Old Welsh scribenn = writing
Middle Welsh (Kymraec) yscriven, ysgriuen = writing
escryuennu, ysgriuennv, sgriuenv = to write
Welsh (Cymraeg) (y)sgrifen [əsˈɡrɪvɛn / ˈsɡrɪvɛn] = writing, manuscript, inscription, handwriting, letter, document, writ, deed, certificate, bill
(y)sgrifenedig = written, recorded, signed
(y)sgrifenlyfr = manuscript, writing-book
(y)sgrifennaf, (y)sgrifennu, sgwennu = to write, note (down), take a census
(y)sgrifennydd = secretary, scribe, clerk, copyist, writer, author
(y)sgrifennyddiaeth = orthography, spelling, handwriting
ysgrafo = to scratch, claw
Old Cornish scriuen = writing
Middle Cornish (Cernewec) screfa, scrife = to write
screft = scripture
scrife = writing
scriven = writing, letter, missive
scriviniat, scriuinat = writer
scrivit, scriut = writing
Cornish (Kernewek) skrif [skriːf] = document, script, writing, article
skrifa = to write, script, writ, writing
skrienyas, skrienyades = secretary
skrifenyaseth = secretariat
skrifer, skrifores = writer
skrifwas = clerk
Middle Breton (Brezonec) skriv, scrihuë = written
skrivadenn = something written
skrivadur = spelling, way of writing
skrivagner = scribe, secretary
skrivailher, skrivantour, skrivagnerez = writer
skrivañ, skriviñ, skriv = to write
Breton (Brezhoneg) skrivad = writing
skrivadenn = dictation
skrivagner = writer
skrivañ = to write

Etymology: from Latin scrībō (I write), from Proto-Italic *skreiβō (I carve), from Proto-Indo-European *(s)kreybʰ- (to scratch, to tear) [source].

Words from the same roots include scribble, scribe, script, shrift and shrive in English, and scritta (writing, notice, sign) and scrìvere (to write, spell) in Italian [source].

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