A very rare verb, and, where found, usually used literally. Isaeus 4.19 has w)stolo/ghsen; Photius, Lexicon omicron567 Theodoridis glosses the present infinitive (as here) as 'to collect bones' (o)sta= sulle/gein), and the Lexica Segueriana has something very similar for the aorist infinitive (probably quoted from Menander, Aspis 77). How it acquired the transferred sense claimed here is not clear.