The headword is the third person singular present indicative form of the deponent verb μνάομαι . This form appears twice in Homer, at Odyssey 16.77 -- the scholia to which provide the gloss here -- and 19.529 (web addresses 1 and 2).
This entry also appears at Photius mu477 and Synagoge mu235. Other forms of this verb appear in the Suda at mu 1147 and mu 1177.
cf. also epsilon 990.