Aci < indoeuropeo *Hₐắk̑ĭ s ‘gelido (pungente)’

Àci (Aci Bonaccorsi, A. Castello, A. Catena, A. Platani, Acireale, A. San Filippo, A. Santa Lucia, A. Sant’Antonio, A. Trezza, in the province of Catania), Sicilian Iàci, also name of a river, silted up by the 1169 Etna eruption: Greek Ἄκις (renowned for its cold water: Ἄκις ποταμός: ἐπὶ τῶν ἄγαν ψυχρῶν. ψυχρὸς γάρ ἐστιν οὗτος, Dĭŏgĕnān. II, 74 = Ăpŏst. I, 96, cfr. III, 12; Ărsĕn. II, 54) < Sicel *Ắkĭ-s < Proto-Indo-European Ắk̑ĭ-s < *Hₐắk̑ĭ-s ← *hₐắk̑ĭ-s (> *ắk̑ĭ-s) ‘sharp’ (of biting cold), adjective of *hₐăk̑ĭ́-s *ăk̑ĭ́-s > Greek ἀκίς ‘point, ‘prickly object’. Other Sicel etymologies: Σῐκελοί <Sĭkĕlŏí̯>, Sĭcŭlī < Proto-Indo-European *Sĭk-ĕlŏ́-ĕs ‘pertaining to the reached (territories)’; Σῑκανίη <Sīkănĭ́ē> ← Σῑκανοί <Sīkănŏí̯> < Proto-Indo-European *Sĭ́h₁kn̥hₓŏ-ĕs < *Sh₁ĭ́-k-n̥hₓŏ-ĕs ÷ *Sh₁ĭ-k-n̥-hₓŏ́-ĕs ‘Farmers’ < ‘pertaining par excellence to the whole of the sown (territories)’; Μελίτη <Mĕlĭ́tē> < Proto-Indo-European *Mĕ́lĭt-ă‧hₐ ← *mĕ́lĭt ‘honey’; Γαῦδος <Găũ̯dŏs> < Proto-Indo-European *G̑ắu̯[hₐ]dʱŏ-s / *Gắu̯[hₐ]dʱŏ-s ← √*g̑ĕhₐu̯(-dʱ)-/√*gĕhₐu̯(-dʱ)- ‘rejoice’; Αἴτνη < Sicel *Ăi̯tnā < Proto-Indo-European *Hₐắi̯t-năhₐ ← √*hₐăi̯-t- ← root √*hₐăi̯- ‘burn, shine’; maf(f)ia (Pre-Norman anti-feudal defence) < Regional Latin *măgfĭhă < *măg[ŏ]fĭhă < Sicel *măgŏ–̊fĭhā < Proto-Indo-European *m̥g̑-ŏ–̊dʱĭg̑ʱ-ă·hₐ ‘great protection’ (of Neolithic origin).