In this post we’re looking into words meaning to suck, to absorb and related things in Celtic languages.

Words marked with a * are reconstructions.

Proto-Celtic	*dinīti = to suck
Old Irish (Goídelc)	denaid, dinid [ˈd̠ʲe.nəðʲ] = to suck
Middle Irish (Gaoidhealg)	denaid, dinid, denand, denait = to suck
Irish (Gaeilge)	diúl [dʲuːlˠ] = sucking, suck diúl = to suck diúlaí = sucker diúlcach = suckling, baby diúlfaíoch = alimentary canal, throat diúlfhiacail = milk-tooth leanbh (an) diúl = suckling
Scottish Gaelic (Gàidhlig)	deoghail [dʲo.al] = suck, suckle deòlagan [dʲɔːl̪ˠagan̪ˠ] = sucker, sth or sb who sucks
Manx (Gaelg)	jiole = to suck, nurse, nourish, draw; sucking jioleyder = sucker, sponger, swab, mop
Proto-Brythonic	*denad = to suck (?)
Middle Welsh (Kymraec)	dener, dennv, denu, devnv = to allure, attract, entice, cajole, inveigle, beguile, decoy denawl = attractive, alluring denwr = enticer, seducer, inveigler, persuader
Welsh (Cymraeg)	denaf, denu [ˈdɛnɨ / ˈdeːni] = to allure, attract, entice, cajole, inveigle, beguile, decoy dengar = alluring, attractive, enticing, winning, charming dengarwch = allurement, winsomeness, enticement, attractiveness deniad = allurement, enticement, attraction, lure, bait, temptation deniadol = attractive, alluring, enticing, engaging, winning denol = attractive, alluring denwr = enticer, seducer, inveigler, persuader
Middle Cornish (Cernewec / Kernuak)	dena, dené, deny = to suck, to draw, to absorb, to withdraw
Cornish (Kernewek)	dena [ˈdɛna / ˈdɛnɐ] = to absorb, to suck denus = absorbing omdhenans = absorbtion
Middle Breton (Brezonec)	denaff = to suckle
Breton (Brezhoneg)	dena = to suck denañ [ˈdẽː.nã] = to suckle dener = sucker, teat cup

Etymology: from Proto-Indo-European *dʰeh₁(y)- (to suckle, to nurse) [source]. Words from the same roots include dia (to suckle) in Swedish, doić (to milk, gulp down) in Polish, femmina (female) in Italian, femme (woman, wife) in French, and female and feminine in English [source].

Proto-Celtic	*sowkno- = to suck
Old Irish (Goídelc)	súigid = to absorb, suck
Middle Irish (Gaoidhealg)	súigid, súgad = to suck, to draw in, to absorb, to attract, act of sucking, absorbing, attracting
Irish (Gaeilge)	sú = absorption, suction súigh = to absorb, suck
Scottish Gaelic (Gàidhlig)	sùigh [suːj] = suck, absorb, lap sùg [suːg] = suck, imbibe
Manx (Gaelg)	soo (stiagh) = to suck (in), to soak (up), to imbibe, to sip; sucking, suction; sap, juice sooder = sucker, soaker, sipper, absorber, tippler, exhaust soolagh = juice, sauce, juicy
Middle Welsh (Kymraec)	sugyn, sugn, svgn = suction, suck, a suckling; juice, sap, liquid, moisture svgney, sugyn, sugnav, sugn = to suck, drink, suckle sugndraeth, sugyndraeth, svgvndraeth = quicksand
Welsh (Cymraeg)	sugn = suction, suck, a suckling, pull, attraction, undertow; juice, sap, liquid, moisture sugnaf, sugno [ˈsɨ̞ɡnɔ / ˈsɪɡnɔ] = to suck, drink, suckle, absorb, draw (out), engulf, attract sugndraeth = quicksand sugnog = sucking amsugno [amˈsɨ̞ɡnɔ / amˈsɪɡnɔ] = to absorb
Cornish (Kernewek)	sugna = to suck sugnans = suction sugnek = succulent, juicy sugnell = juicer sugnus = succulent
Middle Breton (Brezonec)	sunaff = to suck
Breton (Brezhoneg)	sunañ [ˈsỹː.nã] = to suck, to drink, to aspire, to hoover, to deceive sunek = juicy sunell = lollipop, dummy, pacifier suner = nozzle, sucker sunerezh = suction, vacuum cleaner

Etymology: from PIE *sewg- / *sewk- (to suck) [source]. Words from the same PIE root include suck and soak in English, zuigen (to suck, vacuum, suckle, pester) in Dutch, saugen (to suck, download) in German, and sucer (to suck) in French [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 Kernehe, itk, Dictionaire Favereau, TermOfis, English – ProtoCeltic WordList (PDF), Etymological Dictionary Of Proto Celtic