For this adjective see already nu 571. The present entry likewise occurs in Photius (nu323 Theodoridis) and other lexica.
The second of its glosses, o(malo/s, normally means "even, level", a meaning not obviously appropriate here, but LSJ s.v. notes the sense "not remarkable, middling, average" in Theocritus. (Thus there seems no need to adopt Toup's suggested emendation, noted by Theodoridis, to o( milo/s; cf. Hesychius mu1359, nu818.)