ἄκλιτος

From ᾰ̓- (ă-, “un-”) +‎ κλῑ́νω (klī́nō, “to decline”) +‎ -τος (-tos, verbal adjective suffix). Diachronically from Proto-Indo-European *n̥-ḱlitós, formed from the root *ḱley- (“to incline, slope”).

ᾰ̓́κλῐτος • (ắklĭtos) m or f (neuter ᾰ̓́κλῐτον); second declension (Koine)

1. unwavering, stable
   • c. 245 CE – c. 325 CE, Iamblichus Chalcidensis, On the Mysteries 1.15:

     Ἔτι γὰρ μᾶλλον ἀκλίτους καὶ ἀμιγεῖς αἰσθητοῖς εἰπὼν εἶναι τοὺς καθαροὺς νόας ἀπορεῖς (...)

     Éti gàr mâllon aklítous kaì amigeîs aisthētoîs eipṑn eînai toùs katharoùs nóas aporeîs (...)

     You see, having declared that "the pure intellects are unwavering and unmingled with tangible things", you ask still further (...)

   1. (grammar) indeclinable
      • 170 BCE – 90 BCE, Dionysius Thrax, Art of Grammar 19:

        ἐπίρρημά ἐστι μέρος λόγου ἄκλιτον

        epírrhēmá esti méros lógou ákliton

        An adverb is an indeclinable part of speech.

   2. (geometry) (said of a rising perpendicular)

      Synonym: ἀκλινής (aklinḗs)

      • 412 CE – 485 CE, Proclus, A Commentary on the First Book of Euclid's Elements 290F:

        εἰ δὲ δεῖ καὶ θεωρίαν προσθεῖναι τοῖς δύο τούτοις προβλήμασιν, ἔοικεν ἡ μὲν πρὸς ορθὰς ἀναγομένη μιμεῖσθαι ζωὴν αἰρομένην (...) μένουσαν ἄκλιτον πρὸς τὰ χείρονα

        ei dè deî kaì theōrían prostheînai toîs dúo toútois problḗmasin, éoiken hē mèn pròs orthàs anagoménē mimeîsthai zōḕn airoménēn (...) ménousan ákliton pròs tà kheírona

        If we must theorize further on these two problems, it seems that a rising up from a straight resembles an exalted life (...) remaining stable in the face of baser things

• Greek: άκλιτος (áklitos)

• “ἄκλιτος”, in Liddell & Scott (1940) A Greek–English Lexicon, Oxford: Clarendon Press
• ἄκλιτος in the Diccionario Griego–Español en línea (2006–2025)
• ἄκλιτος in Bailly, Anatole (1935) Le Grand Bailly: Dictionnaire grec-français, Paris: Hachette
• “ἄκλιτος”, in ΛΟΓΕΙΟΝ Dictionaries for Ancient Greek and Latin (in English, French, Spanish, German, Dutch and Chinese), University of Chicago, since 2011