Another etymology relates the name to a Proto-Indo-European compound "*h₂eḱ-pṓds" "sharp foot" which first gave an Illyrian "*āk̂pediós", evolving through time into "*ākhpdeós" and then "*akhiddeús". The shift from "-dd-" to "-ll-" is then ascribed to the passing of the name into Greek via a Pre-Greek source. The first root part "*h₂eḱ-" "sharp, pointed" also gave Greek ἀκή ("akḗ" "point, silence, healing"), ἀκμή ("akmḗ" "point, edge, zenith") and ὀξύς ("oxús" "sharp, pointed, keen, quick, clever"), whereas ἄχος stems from the root "*h₂egʰ-" "to be upset, afraid". The whole expression would be comparable to the Latin "acupedius" "swift of foot". Compare also the Latin word family of "aciēs" "sharp edge or point, battle line, battle, engagement", "acus" "needle, pin, bodkin", and "acuō" "to make pointed, sharpen, whet; to exercise; to arouse" (whence "acute"). Some topical epitheta of Achilles in the "Iliad" point to this "swift-footedness", namely ποδάρκης δῖος Ἀχιλλεὺς ("podárkēs dĩos Achilleús" "swift-footed divine Achilles") or, even more frequently, πόδας ὠκὺς Ἀχιλλεύς ("pódas ōkús Achilleús" "quick-footed Achilles").