Same or similar entry elsewhere: see the references at Photius mu307 Theodoridis. The headword is aorist active participle. masculine nominative singular, of metaba/llw (cf. mu 753). It must be quoted from somewhere; suggestions include Plato, Philebus 51A (Naber) and Job 10.8 LXX (Alberti, cf. Latte), but there are numerous other possibilities besides.
For related words (nouns), see mu 681 and mu 682.