The unglossed headword is either masculine accusative singular or neuter nominative/accusative singular of the adjective e)feto/s; masculine accusative if it is extracted from the quotation given -- but see next note.
[1] An approximation of Synesius, Dio 12 (PG 66.1148a). Here the words are rearranged, and the Suda's e)feto/n should be e)feth/n. [LSJ s.v. does not register this sense, alongside (I) 'desirable' and (II, epigraphically attested) 'annual', but the context demands it, and cf. in any event LSJ s.v. e)fe/ths, III.]