The headword is presumably extracted from the quotation given; at any rate it is not attested elsewhere. It is the masculine (and feminine) form of the two-ending adjective murie/liktos, -on; see generally LSJ s.v.
[1] The mythological granddaughter of Helios (OCD(4) s.v.), Medea (OCD(4) s.v.) fled her native Colchis (OCD(4) s.v., kappa 1979, and generally Barrington Atlas map 88 grid A2) with Jason after having wielded her sorcery to aid his filching of the golden fleece; cf. mu 878.
[2] The quotation is Eunapius fr. 68 FHG (4.44); cf. Blockley, pp. 124-5 and kappa 408.
The identity of the "foul serpent" is uncertain. In a note to Eunapius fr. 68 FHG (4.44) Müller, Boissonade suggested either Eutropius (epsilon 3776 and epsilon 3777) or Rufinus (rho 240). Eutropius is indeed characterized as a serpent elsewhere by Eunapius (cf. pi 1293); and Rufinus' résumé includes his having succumbed to a false sense of security prior to his assassination by soldiers nominally under his rule, but loyal in fact to an adversary, Stilicho (sigma 1032). Another possibility, suggested by Blockley (p. 150), is Ablabius (cf. PLRE s.v. Ablabius(4)).
[In her critical apparatus Adler reports that ms G substituted polu\s (large) for baru\s, literally heavy; that H. Stephanus deleted the parenthetical remark; and that Jonathan Toup, comparing this passage with kappa 408, excised and succumbing.]