ἰός

See also: ιός, Ίος, and -ιος

Ancient Greek

Etymology 1

From Proto-Hellenic *ihwós, a thematicization of Proto-Indo-European *(H)isu- (“arrow”). Cognates include Sanskrit इषु (íṣu, “arrow”) and Avestan 𐬌𐬱𐬎 (išu, “arrow”).^[1]

Pronunciation

(5^th BCE Attic) IPA^(key): /iː.ós/
(1^st CE Egyptian) IPA^(key): /iˈos/
(4^th CE Koine) IPA^(key): /iˈos/
(10^th CE Byzantine) IPA^(key): /iˈos/
(15^th CE Constantinopolitan) IPA^(key): /iˈos/

Noun

ῑ̓ός • (īós) m (genitive ῑ̓οῦ); second declension

arrow
- c. 800 BCE – 600 BCE, Homer, Iliad 1.48:
  ἕζετ’ ἔπειτ’ ἀπάνευθε νεῶν, μετὰ δ’ ἰὸν ἕηκε
  hézet’ épeit’ apáneuthe neôn, metà d’ iòn héēke
  Then he sat down apart from the ships and let fly an arrow.

Declension

Second declension of ὁ ῑ̓ός; τοῦ ῑ̓οῦ (Attic)

Case / #	Singular	Dual	Plural
Nominative	ὁ ῑ̓ός ho īós	τὼ ῑ̓ώ tṑ īṓ	οἱ ῑ̓οί hoi īoí
Genitive	τοῦ ῑ̓οῦ toû īoû	τοῖν ῑ̓οῖν toîn īoîn	τῶν ῑ̓ῶν tôn īôn
Dative	τῷ ῑ̓ῷ tōî īōî	τοῖν ῑ̓οῖν toîn īoîn	τοῖς ῑ̓οῖς toîs īoîs
Accusative	τὸν ῑ̓όν tòn īón	τὼ ῑ̓ώ tṑ īṓ	τοὺς ῑ̓ούς toùs īoús
Vocative	ῑ̓έ īé	ῑ̓ώ īṓ	ῑ̓οί īoí
Notes:	This table gives Attic inflectional endings. For declension in other dialects, see Appendix:Ancient Greek dialectal declension.

Heteroclitic neuter plural:

Second declension of τᾰ̀ ῑ̓ᾰ́; τῶν ῑ̓ῶν (Attic)

Case / #	Plural
Nominative	τᾰ̀ ῑ̓ᾰ́ tằ īắ
Genitive	τῶν ῑ̓ῶν tôn īôn
Dative	τοῖς ῑ̓οῖς toîs īoîs
Accusative	τᾰ̀ ῑ̓ᾰ́ tằ īắ
Vocative	ῑ̓ᾰ́ īắ
Notes:	This table gives Attic inflectional endings. For declension in other dialects, see Appendix:Ancient Greek dialectal declension.

Derived terms

ἰαφέτης (iaphétēs)
ἰοβόλος (iobólos)
ἰοδόκος (iodókos)
ἰοτυπής (iotupḗs)
ἰοχέαιρα (iokhéaira)

Etymology 2

From Proto-Hellenic *wihós, from Proto-Indo-European *wisós (“fluidity, slime, poison”). Cognates include Sanskrit विष (víṣa), Latin vīrus, Tocharian A wäs, Tocharian B wase, and Middle Irish fí.^[2]

Pronunciation

(5^th BCE Attic) IPA^(key): /iː.ós/
(1^st CE Egyptian) IPA^(key): /iˈos/
(4^th CE Koine) IPA^(key): /iˈos/
(10^th CE Byzantine) IPA^(key): /iˈos/
(15^th CE Constantinopolitan) IPA^(key): /iˈos/

Noun

ῑ̓ός • (īós) m (genitive ῑ̓οῦ); second declension

poison, venom
- :
  καὶ μὴ τυχοῦσαι πράγματος νικηφόρου, χώρᾳ μεταῦθις ἰὸς ἐκ φρονημάτων πέδοι πεσὼν ἄφερτος αἰανὴς νόσος
  kaì mḕ tukhoûsai prágmatos nikēphórou, khṓrāi metaûthis iòs ek phronēmátōn pédoi pesṑn áphertos aianḕs nósos
  And if they fail to win their cause, the venom from their resentment will fall upon the ground, an intolerable, perpetual plague afterwards in the land.

Inflection

Second declension of ὁ ῑ̓ός; τοῦ ῑ̓οῦ (Attic)

Case / #	Singular	Dual	Plural
Nominative	ὁ ῑ̓ός ho īós	τὼ ῑ̓ώ tṑ īṓ	οἱ ῑ̓οί hoi īoí
Genitive	τοῦ ῑ̓οῦ toû īoû	τοῖν ῑ̓οῖν toîn īoîn	τῶν ῑ̓ῶν tôn īôn
Dative	τῷ ῑ̓ῷ tōî īōî	τοῖν ῑ̓οῖν toîn īoîn	τοῖς ῑ̓οῖς toîs īoîs
Accusative	τὸν ῑ̓όν tòn īón	τὼ ῑ̓ώ tṑ īṓ	τοὺς ῑ̓ούς toùs īoús
Vocative	ῑ̓έ īé	ῑ̓ώ īṓ	ῑ̓οί īoí
Notes:	This table gives Attic inflectional endings. For declension in other dialects, see Appendix:Ancient Greek dialectal declension.

Derived terms

ἰοβόλος (iobólos)
ἰοβόρος (iobóros)
ἰοδόκος (iodókos)
ἰοειδής (ioeidḗs)
ἰόεις (ióeis)
ἰολόχευτος (iolókheutos)
ἰομιγής (iomigḗs)
ἰοτόκος (iotókos)
ἰοφόρος (iophóros)
ἰώδης (iṓdēs)

Descendants

Greek: ιός m (iós, “venom”)

Etymology 3

Uncertain. May be of the same origin as Etymology 2.^[3]

Pronunciation

(5^th BCE Attic) IPA^(key): /iː.ós/
(1^st CE Egyptian) IPA^(key): /iˈos/
(4^th CE Koine) IPA^(key): /iˈos/
(10^th CE Byzantine) IPA^(key): /iˈos/
(15^th CE Constantinopolitan) IPA^(key): /iˈos/

Noun

ῑ̓ός • (īós) m (genitive ῑ̓οῦ); second declension

rust, verdigris
- 375 BCE, Plato, The Republic 609a:
  κακὸν ἑκάστῳ τι καὶ ἀγαθὸν λέγεις; οῖον ὀφθαλμοῖς ὀφθαλμίαν […] χαλκῷ δὲ καὶ σιδήρῳ ἰόν
  kakòn hekástōi ti kaì agathòn légeis? oîon ophthalmoîs ophthalmían […] khalkōî dè kaì sidḗrōi ión
  Do you say that there is for everything its special good and evil, as for the eyes ophthalmia […] and for bronze and iron rust?

Inflection

Second declension of ὁ ῑ̓ός; τοῦ ῑ̓οῦ (Attic)

Case / #	Singular	Dual	Plural
Nominative	ὁ ῑ̓ός ho īós	τὼ ῑ̓ώ tṑ īṓ	οἱ ῑ̓οί hoi īoí
Genitive	τοῦ ῑ̓οῦ toû īoû	τοῖν ῑ̓οῖν toîn īoîn	τῶν ῑ̓ῶν tôn īôn
Dative	τῷ ῑ̓ῷ tōî īōî	τοῖν ῑ̓οῖν toîn īoîn	τοῖς ῑ̓οῖς toîs īoîs
Accusative	τὸν ῑ̓όν tòn īón	τὼ ῑ̓ώ tṑ īṓ	τοὺς ῑ̓ούς toùs īoús
Vocative	ῑ̓έ īé	ῑ̓ώ īṓ	ῑ̓οί īoí
Notes:	This table gives Attic inflectional endings. For declension in other dialects, see Appendix:Ancient Greek dialectal declension.

Derived terms

ἰάζω (iázō)
ἰίζω (iízō)
ἰόομαι (ióomai)
ἰοποίησις (iopoíēsis)
ἰώδης (iṓdēs)

Etymology 4

Expansion of original feminine-only pronoun ἴᾱ (íā), from *(h₁)éy.^[4]

Pronunciation

(5^th BCE Attic) IPA^(key): /i.ós/
(1^st CE Egyptian) IPA^(key): /iˈos/
(4^th CE Koine) IPA^(key): /iˈos/
(10^th CE Byzantine) IPA^(key): /iˈos/
(15^th CE Constantinopolitan) IPA^(key): /iˈos/

Adjective

ῐός • (ĭós) m (feminine ῐ̓́ᾰ, neuter ῐ̓όν); first/second declension

selfsame; identical

Inflection

First and second declension of ῐ̓ός; ῐ̓́ᾰ; ῐ̓όν (Attic)

Number	Singular			Dual			Plural
Case/Gender	Masculine	Feminine	Neuter	Masculine	Feminine	Neuter	Masculine	Feminine	Neuter
Nominative	ῐ̓ός ĭós	ῐ̓́ᾰ ĭ́ă	ῐ̓όν ĭón	ῐ̓ώ ĭṓ	ῐ̓ᾱ́ ĭā́	ῐ̓ώ ĭṓ	ῐ̓οί ĭoí	ῐ̓αί ĭaí	ῐ̓ᾰ́ ĭắ
Genitive	ῐ̓οῦ ĭoû	ῐ̓ᾶς ĭâs	ῐ̓οῦ ĭoû	ῐ̓οῖν ĭoîn	ῐ̓αῖν ĭaîn	ῐ̓οῖν ĭoîn	ῐ̓ῶν ĭôn	ῐ̓ῶν ĭôn	ῐ̓ῶν ĭôn
Dative	ῐ̓ῷ ĭōî	ῐ̓ᾷ ĭāî	ῐ̓ῷ ĭōî	ῐ̓οῖν ĭoîn	ῐ̓αῖν ĭaîn	ῐ̓οῖν ĭoîn	ῐ̓οῖς ĭoîs	ῐ̓αῖς ĭaîs	ῐ̓οῖς ĭoîs
Accusative	ῐ̓όν ĭón	ῐ̓́ᾰν ĭ́ăn	ῐ̓όν ĭón	ῐ̓ώ ĭṓ	ῐ̓ᾱ́ ĭā́	ῐ̓ώ ĭṓ	ῐ̓ούς ĭoús	ῐ̓ᾱ́ς ĭā́s	ῐ̓ᾰ́ ĭắ
Vocative	ῐ̓έ ĭé	ῐ̓́ᾰ ĭ́ă	ῐ̓όν ĭón	ῐ̓ώ ĭṓ	ῐ̓ᾱ́ ĭā́	ῐ̓ώ ĭṓ	ῐ̓οί ĭoí	ῐ̓αί ĭaí	ῐ̓ᾰ́ ĭắ
Derived forms	Adverb			Comparative			Superlative
Derived forms	ῐ̓ῶς ĭôs			ῐ̓ώτερος ĭṓteros			ῐ̓ώτᾰτος ĭṓtătos
Notes:	This table gives Attic inflectional endings. For declension in other dialects, see Appendix:Ancient Greek dialectal declension.

References

^ Beekes, Robert S. P. (2010), “ῑ̓ός 2”, in Etymological Dictionary of Greek (Leiden Indo-European Etymological Dictionary Series; 10), volume I, with the assistance of Lucien van Beek, Leiden, Boston: Brill, →ISBN, page 595
^ Beekes, Robert S. P. (2010), “ῑ̓ός 3”, in Etymological Dictionary of Greek (Leiden Indo-European Etymological Dictionary Series; 10), volume I, with the assistance of Lucien van Beek, Leiden, Boston: Brill, →ISBN, page 595
^ Beekes, Robert S. P. (2010), “ῑ̓ός 4”, in Etymological Dictionary of Greek (Leiden Indo-European Etymological Dictionary Series; 10), volume I, with the assistance of Lucien van Beek, Leiden, Boston: Brill, →ISBN, page 595
^ Beekes, Robert S. P. (2010), “ἴα”, in Etymological Dictionary of Greek (Leiden Indo-European Etymological Dictionary Series; 10), volume I, with the assistance of Lucien van Beek, Leiden, Boston: Brill, →ISBN, page 571

Ancient Greek

Etymology 1

Pronunciation

Noun

Declension

Derived terms

Etymology 2

Pronunciation

Noun

Inflection

Derived terms

Descendants

Etymology 3

Pronunciation

Noun

Inflection

Derived terms

Etymology 4

Pronunciation

Adjective

Inflection

References

Further reading