-ως

• -ω (-ō)

Beekes states that this common adverbial suffix cannot be demonstrated to go back to the Proto-Indo-European era.^[1]

-ως • (-ōs)

1. Added to the stem of adjectives or pronouns to form adverbs

   ‎ἄξιος (áxios, “worthy”) + ‎-ως (-ōs) → ‎ἀξίως (axíōs, “worthily”)

From Proto-Indo-European *-ōs.

-ως • (-ōs) m or f (genitive -οῦς); third declension

1. (unproductive) Added to verbal roots to form a noun of result or an abstract noun of action.

• ἠώς f (ēṓs)
• αἰδώς f (aidṓs)
• γέλως m (gélōs)
• ἱδρώς m (hidrṓs)
• αἰῶ m (aiô)

Smyth, Herbert Weir (1920), “Part II: Inflection”, in A Greek grammar for colleges, Cambridge: American Book Company, § 341