[163] ἀλαστήσας, only here, 15.21 “ἠλάστεον δὲ θεοί”, and Od. 1.252 “ἐπαλαστήσασα”. The explanation of the word depends on that of “ἄλαστος”, which is generally derived from “λαθ”, in the sense not to be forgotten, which suits wherever it is an epithet of “ἄχος” or “πένθος”. But in 22.261 “Ἕκτορ ἄλαστε” this will not do, nor is it easy to deduce the sense of the verb from it (‘to feel things intolerable, lit. not to be forgotten,’ hence ‘to break out in protest,’ as Monro and others explain, is very artificial). It is preferable with some of the ancient grammarians to derive “ἄλαστος” (or perhaps rather “ἀλαστός”) from *“ἀλάζω”, a by-form of “ἀλά-ομαι” with the sense of “ἀλύω”. The adjective will then mean ‘mad,’ distraught, and the verb “ἀλαστέω”, to be distressed, at one's wit's end.
