The headword is genitive singular of the feminine adjective maieutikh/, attested in literal and figurative senses. Same or similar entry in other lexica (see the references to Photius mu26 Theodoridis). The headword must be quoted from somewhere, probably (as Naber suggested) Plato, Theaetetus 161E; see also Politicus 268A.
See also mu 315, mu 316, mu 317, mu 319, mu 320, mu 341, mu 345.