αἰέν (aien)
αἰέν is an Ancient Greek form of ἀεί, meaning “always, ever”. It is the adverb.
Found 221 times in the Ancient Greek texts on Socratos.
Where it is used
Apollonius Rhodius, Argonautica 1.499: ἠδʼ ὡς ἔμπεδον αἰὲν ἐν αἰθέρι τέκμαρ ἔχουσιν
Homeric Hymns, Hymn 2 to Demeter 25: ἄιεν ἐξ ἄντρου, Ἑκάτη λιπαροκρήδεμνος,
Pindar, Pythian 3.27: οὐδʼ ἔλαθε σκοπόν· ἐν δʼ ἄρα μηλοδόκῳ Πυθῶνι τόσσαις ἄϊεν ναοῦ βασιλεὺς
Source: Socratos (socratos.org), a free reader for Ancient Greek and Latin. Grammar from the Perseus Treebank and Morpheus; dictionary entries from Liddell-Scott-Jones, A Greek-English Lexicon (Perseus Digital Library, CC BY-SA). Counts are from the texts on Socratos.