This etymology, as the competing one ἄρκτος / ἀρκέω, appeals to the characteristic of hibernation which makes the animal seem idle or lazy – it is a descriptive etymology. The form ἀργή, following the s-inflection, is secondary: it is from ἀεργός, so that it has a long /ā/, whereas ἄρκτος has a short /ă/, but phonological vocalic quantity was lost in Greek when this etymology was devised. No phonetic manipulation is involved, the /g/ becomes voiceless before the /t/ of the suffix.