Words for cattle, cow, bull and calf in Celtic languages.

| Proto-Celtic |
*bāus = cow |
| Old Irish (Goídelc) |
bó [boː] = ox, cow |
| Irish (Gaeilge) |
bó [bˠoː] = cow |
| Scottish Gaelic (Gàidhlig) |
bò [boː] = cow |
| Manx (Gaelg) |
booa = cow |
| Proto-Brythonic |
*bʉ = cow |
| Middle Welsh (Kymraec) |
bu(w) = cow |
| Welsh (Cymraeg) |
bu, buw, buyn = cow, bullock, head of cattle
biw = cow, cattle, horned cattle |
| Cornish (Kernewek) |
bu = cow |
| Breton (Brezhoneg) |
bu = cow |
Etymology: from the Proto-Indo-European *gʷṓws (cattle) [source].
| Proto-Celtic |
*boukkā = cow |
| Proto-Brythonic |
*bʉx = cow |
| Middle Welsh (Kymraec) |
buch = cow |
| Welsh (Cymraeg) |
buwch [bɨu̯χ / bɪu̯χ] = cow |
| Old Cornish |
buch = cow |
| Middle Cornish |
bugh, biuh = cow |
| Cornish (Kernewek) |
bugh, buwgh [biʊx / bɪwh] = cow |
| Breton (Brezhoneg) |
buoc’h [ˈbɥoːχ / ˈbyːɔχ] = cow |
Etymology: from the Proto-Celtic *bāus (cow), the Proto-Indo-European *gʷṓws (cattle) [source].
| Proto-Celtic |
*tarwos = bull |
| Gaulish |
taruos = bull |
| Old Irish (Goídelc) |
tarb [tarv] = bull |
| Irish (Gaeilge) |
tarbh [ˈt̪ˠaɾˠuː / ˈt̪ˠaɾˠu] =bull |
| Scottish Gaelic (Gàidhlig) |
tarbh [tarav] = bull, Taurus |
| Manx (Gaelg) |
tarroo = bull |
| Proto-Brythonic |
*tarw = bull |
| Middle Welsh (Kymraec) |
tarw = bull |
| Welsh (Cymraeg) |
tarw [ˈtaru / ˈtaːru] = bull, uncastrated male ox, papal bull, Taurus (sign of the zodiac) |
| Old Cornish |
tarow = bull |
| Cornish (Kernewek) |
tarow = bull |
| Old Breton |
taruu = bull |
| Middle Breton |
taru = bull |
| Breton (Brezhoneg) |
tarv = bull |
Etymology: from the Proto-Indo-European *táwros (wild bull, aurochs) [source].
| Proto-Celtic |
*laygos / *lāɸigos = calf |
| Old Irish (Goídelc) |
lóeg [l͈oːi̯ɣ] = calf, favourite, darling |
| Irish (Gaeilge) |
lao [l̪ˠeː / l̪ˠiː] = (young) calf |
| Scottish Gaelic (Gàidhlig) |
laogh [l̪ˠɯːɣ] = calf, kid (of deer), fawn, term of endearment for a child |
| Manx (Gaelg) |
lheiy [ax] = calf |
| Middle Welsh (Kymraec) |
lloe, lloi = calf |
| Welsh (Cymraeg) |
llo [ɬoː] = calf, bullock, simpleton, dolt |
| Old Cornish |
loch = calf |
| Middle Cornish) |
lugh = calf |
| Cornish (Kernewek) |
leugh [løːx / leːx / lɛwh] = calf |
| Breton (Brezhoneg) |
leue [ˈlø.e] = calf |
Etymology: a diminutuve of the Proto-Indo-European *leh₂p- (cattle) [source].
| Irish (Gaeilge) |
bearach = heifer, young cow |
| Scottish Gaelic (Gàidhlig) |
biorach [birəx] = a weaned but not fully mature calf or foal (up to 2 years); anti-suckling device, sucking preventer, weaner |
| Welsh (Cymraeg) |
bustach / bustych = bullock, ox, steer (possibly related to the above words) |
Etymology: from the Old Irish berach [ˈbʲerax] (pointed, sharp; having pointed ears, horned), from bir (stake, spit, point; spear, spike) & -ach (related to, having, characterised by, prone to) [source].
| Proto-Brythonic |
*oti̯on- = bullock |
| Middle Welsh (Kymraec) |
eydyon, eidon = ox, steer, bullock |
| Welsh (Cymraeg) |
eidion = domestic male of the bovine family, ox, steer, bullock, neat |
| Old Cornish |
odion = bullock |
| Middle Cornish |
udzheon, odgan = bullock |
| Cornish (Kernewek) |
ojyon = ox |
| Middle Breton |
eugenn = bullock. ox |
| Breton (Brezhoneg) |
ejon = bullock. ox |
| Proto-Celtic |
*anderā = young woman |
| Gaulish |
anderon = heifer |
| Old Irish (Goídelc) |
ainder [ˈan͈ʲdʲər] = married woman; virgin, maiden |
| Middle Irish (Gaoidhealg) |
ander [ˈæn̠ʲəɾˠ] = girl, maiden, lass; young woman |
| Irish (Gaeilge) |
ainnir [ˈæn̠ʲəɾˠ] = girl, maiden, lass; young woman (poetic); attractive woman |
| Scottish Gaelic (Gàidhlig) |
ainnir [an̠ʲɪrʲ] = maiden, virgin; nymph; marriageable woman; young woman |
| Middle Welsh (Kymraec) |
anneir = heifer |
| Welsh (CymraeG) |
anner [ˈanɛr] = heifer |
| Old Cornish |
annoer = heifer |
| Cornish (Kernewek) |
annor = heifer |
| Middle Breton |
annoer = heifer |
| Breton (Brezhoneg) |
annoar = heifer |
Etymology: possibly related to Basque andere (lady, woman) [source].
Words marked with a * are reconstructions.
Sources: Wiktionary, Am Faclair Beag, MacBain’s Dictionary, teanglann.ie, On-Line Manx Dictionary, Geiriadur Prifysgol Cymru, Gerlyver Kernewek, Dictionnaire Favereau