Indo-European etymology :

Proto-IE: *s(w)okʷ- (Gr *h-)

Nostratic etymology:

Meaning: juice, pitch, tar

Tokharian: A saku, B sekwe (PT *sekwe) 'pus' (Adams 698)

Old Greek: opó-s m. `Pflanzensaft', insbes. `der Saft des Feigenbaums, der zum Gerinnen der Milch gebraucht wurde, Feigenlab'

Slavic: *sòkъ

Baltic: *sak-a- m., *sak-ā̂ f., *swak-ā̂ f., -a- c, *swek-a- c.

Albanian: ǵak Blut

Russ. meaning: сок, смола (живица)

References: WP II 515 f

Vasmer's dictionary :

Baltic etymology :

Proto-Baltic: *sak-a- m., *sak-ā̂ f., *swak-ā̂ f., -a- c, *swek-a- c.

Meaning: pitch, tar

Indo-European etymology:

Lithuanian: sãka-s `Harztropfen, -stück', pl. sakaĩ `Harz'; (Miežinis) sveka-s `Harz'

Lettish: sakas pl. (Elger Diction., 137) 'Harz', (Westkurland) saki pl. `Harz'; pl. svakas `Harz', svaki pl. `Milch vor der Geburt'; svęki pl. `Harz'

Old Prussian: sackis `Harz' V. 598

Nostratic etymology :

Eurasiatic: *sVḳV ( ˜ š-)

Meaning: juice, ferment

Borean:

Indo-European: *su̯okʷ-, *soukʷ-

Altaic: *săk`V

Comments: Cf. *[s]iKV

References: МССНЯ 366; ND 2193 *ŝ/śu(ʔa)ḲV(ŕV) 'resin, gum' (with dub. Ur.; on Drav. cf. *CiKV); 2697 *ẑUḲ[ü] 'juice' (IE + diff. Alt. + Irq.).

Altaic etymology :

Proto-Altaic: *săk`V

Nostratic:

Meaning: to ferment

Russian meaning: бродить, сочиться

Turkic: *sakɨŕ / *sagɨŕ

Mongolian: *saga- / *saka-

Tungus-Manchu: *saku

Korean: *sàk- / sǝ̀k-

Comments: EAS 91, KW 308, SKE 220 (Doerfer's skepticism in TMN 3, 255 is hardly justified). The variation of *-g- and *-k- in Turkic and Mongolian is suspicious (cf. also the Nanai form pointing rather to *-k-), perhaps indicating that we are dealing with a merger of two different roots - cf. also the variety of reflexes in Korean; cf. also *sak`o and *zi̯úko.

Turkic etymology :

Proto-Turkic: *sakɨŕ / *sagɨŕ

Altaic etymology:

Meaning: gum, resin

Russian meaning: смола, мастика

Karakhanid: saɣɨz, saqɨz (MK)

Turkish: sakɨz

Tatar: saɣɨz

Middle Turkic: saqɨz (IM, Pav. C.)

Uzbek: saɣiz

Uighur: seɣiz

Azerbaidzhan: saɣɣɨz

Turkmen: saqɨz

Khakassian: sās

Oyrat: saŋɨs

Chuvash: soɣъr

Yakut: ɨas

Dolgan: ɨas

Tuva: sāt

Kirghiz: saɣɨz

Kazakh: saɣɨz

Noghai: saɣɨz

Bashkir: haɣɨz

Gagauz: saqɨz

Karaim: saqɨz

Karakalpak: saɣɨz

Kumyk: saɣɨz

Comments: EDT 817-818, VEWT 396, Лексика 117-118, ЭСТЯ 7, Федотов 2, 70, Stachowski 258. Cf. also *sakɨŕ 'clay' (Лексика 375, ЭСТЯ 7 ibid.). MK glosses saɣɨz as 'gum, resin', and saqɨz as 'any viscous substance', so a merger of two original roots is not excluded.

Mongolian etymology :

Proto-Mongolian: *saga- / *saka-

Altaic etymology:

Meaning: to ferment, to trickle

Russian meaning: бродить, сочиться

Written Mongolian: saɣa-

Khalkha: saga-

Buriat: haxaj- 'to become covered with mud' (?)

Kalmuck: saxǝ-

Comments: KW 308.

Tungus etymology :

Proto-Tungus-Manchu: *saku

Altaic etymology:

Meaning: 1 stale water, muddy water 2 to become turbid, make turbid (of water)

Russian meaning: 1 застоявшаяся, ржавая вода 2 мутнеть, мутить (воду)

Evenki: šaka- (Kamn.) 2

Even: saq 1, saqab- 2 (Arm.)

Nanai: saqo / saqụ 1

Comments: ТМС 2, 56, 80-81.

Korean etymology :

Proto-Korean: *sàk- / *sǝ̀k-

Altaic etymology:

Meaning: 1 to exude, effervesce, ferment 2 to rot, become spoiled 3 ferment, yeast

Russian meaning: 1 киснуть, бродить, выделяться (о поте, пузырьках из воды etc.) 2 гнить, портиться 3 фермент, закваска

Modern Korean: sak- 1, s:ǝk- 2, sǝgim 3

Middle Korean: sàk- 1, sǝ̀k- 2, sǝ̀kím 3

Comments: Liu 435, 448, 450, KED 888, 940.

Long-range etymologies :

Borean (approx.) : CVKV

Meaning : sour, ferment

Eurasiatic : *sVḳV ( ˜ ś-, š-, ć`-)

Afroasiatic : *sVḳʷ- (or to Nostr. *SiḳV- 'urinate, pour' 814?)

Sino-Caucasian : *c̣ǟ́xḳwV

African (misc.) : Cf. Macro-Khoisan *c̮^ku "dew" or *cVkV "sap".

Reference : ND 2036, 2042

Afroasiatic etymology :

Proto-Afro-Asiatic: *sVḳʷ-

Meaning: drink

Borean etymology:

Semitic: *šVḳ- 'drink' 1, 'give a drink' 2

Western Chadic: *suḳ- 'give water (to a child)'

Central Chadic: *sVḳwa- 'drink'

Notes: Cf. also *sVḳw- 'honey' (Cush., Chad., see ND 2037).

Semitic etymology :

Number: 1469

Proto-Semitic: *šVḳ-

Afroasiatic etymology:

Meaning: 'drink' 1, 'give a drink' 2

Akkadian: šaqû 2

Ugaritic: šqy 1

Hebrew: šqh 2

Arabic: sqy 1, 2

Jibbali: šeḳe 2

West Chadic etymology :

Proto-WChadic: *swaḳ-

Afroasiatic etymology:

Meaning: 'give water (to a child)'

Tangale: soke [JgT]

Central Chadic etymology :

Proto-CChadic: *sVḳwa-

Afroasiatic etymology:

Meaning: 'drink'

Higi Nkafa: sexwì {KrN 338]

Higi Ghye: sɛgwi [Kr]

Fali Gili: sɛgwi

Kapsiki=Higi Kamale: sakwù [CLR: 111]

Notes: spirantization of a velar under the influence of a sibilant in anlaut

Sino-Caucasian etymology :

Proto-Sino-Caucasian: *c̣ǟ́xḳwV

Meaning: sour, bitter

Borean etymology:

North Caucasian: *c̣_ǟḳwV

Sino-Tibetan: *săk

Burushaski: *ṣuqúr

Basque: *gac

Comments and references : DCE 30.

North Caucasian etymology :

Proto-North Caucasian: *c̣_ǟḳwV

Sino-Caucasian etymology:

Meaning: sour, raw

Proto-Avaro-Andian: *c̣:iḳ:ʷV-

Proto-Tsezian: *c[ɨ]q- / *c[ɨ]q̇-

Proto-Lak: c:iẋku-

Proto-Dargwa: *c̣iḳʷ-

Proto-Lezghian: *c̣äḳʷɨ-

Notes: Reconstructed for the PEC level. A possible WC parallel see under *ɦmVjć̣_wĂ 'sour'.

Andian etymology :

Protoform: *c̣:iḳ:ʷV-

North Caucasian etymology:

Meaning: sour

Avar: c̣:éḳa-b

Chadakolob: c̣éḳa-b

Andian language: c̣:iḳ:u

Akhvakh: č̣:iḳ:u-da-

Chamalal: ṣiḳu-b

Tindi: c:ik:u-b

Karata: c̣:iḳ:o-b

Botlikh: c̣:iḳ:u

Bagvalal: c̣:iḳu-

Godoberi: c:ik:u

Comments: For Avar the Av.-Rus. dictionary gives c̣:eḳa-b (with ḳ), but Gudava (1964, 105) writes c̣:eḳ:a-b; the variant with weak -ḳ- may be due to dissimilation. Unclear is č̣:- in Akhvakh (all other languages uniformly point to *c̣:-).

Tsezian etymology :

Proto-Tsezian: *c[ɨ]q- / *c[ɨ]q̇-

North Caucasian etymology:

Meaning: sour

Tsezi: ceq̇(i)ju

Ginukh: ceq̇q̇u

Khvarshi: caqu

Inkhokvari: caqqu

Comments: PTsKh *c[ɨ]qV-ju / *c[ɨ]q̇V-ju. The vowel correspondence is irregular (unclear is -a- in Khvarsh. and Inkh.). The variation *q/*q̇ is rather typical for reflexes of PEC glottalized consonants in "tense" words.

Lak etymology :

Lak root: c:iẋku-

North Caucasian etymology:

Meaning: sour

Lak form: c:iẋku- (Khosr.)

Comments: Attested only in Khosrekh. The normal Laki reflex of PEC *c̣ǟḳ_wV- would be *c:iḳu-. -ẋk- is not clear (perhaps under influence of c:iẋ 'manure, dung'?).

Dargwa etymology :

Proto-Dargwa: *c̣iḳʷ-

North Caucasian etymology:

Meaning: sour

Akusha: c̣iḳ-si

Comments: Cf. also Tsud. c̣iḳʷ-se, Kharb. c̣aḳ-se, Kait. c̣ig-dihaw id.

Lezghian etymology :

Proto-Lezghian: *c̣äḳʷɨ-

North Caucasian etymology:

Meaning: 1 raw 2 rank, bitter

Lezghian: ciḳi 1

Archi: c̣egʷ-du- 2

Comment: Arch. predic. c̣eḳʷ 'to be rank, bitter'.

Sino-Tibetan etymology :

Proto-Sino-Tibetan: *săk

Sino-Caucasian etymology:

Meaning: bitter, pungent

Burmese: sak be bitter.

Kachin: mǝsaʔ² be sharp, biting to the taste.

Lushai: thak be pungent, hot, peppery.

Burushaski etymology :

Common Burushaski: *ṣuqúr

Sino-Caucasian Etymology:

Meaning: 1 to turn sour 2 sour

Yasin: iṣqórum 2

Hunza: -ṣqur- 1, ṣuqúrum 2

Nagar: -ṣqur- 1, ṣuqúrum 2

Basque etymology :

Proto-Basque: *gac

Sino-Caucasian etymology:

Meaning: salt

Bizkaian: gatz

Gipuzkoan: gatz

High Navarrese: gatz

Low Navarrese: gatz

Lapurdian: gatz

Zuberoan: gatz

Roncalese: gatz