The headword is a product of late Greek, and is rare outside patristic literature (and lexicography).
That this nominative singular feminine noun is glossed here with a redundant combination of an infinitive and an adverb is probably a result of misreading. The Lexica Segueriana (215.9 Bachmann) has an entry for the dative singular form of the noun e)kfantori/a|, 'with revelation', which it glosses more cogently as e)kfanw=s, fanerw=s: 'conspicuously', 'clearly'. The loss of the iota-subscript in the headword and the corruption of e)kfanw=s, fanerw=s into the Suda's e)kfanw=s fanerw=sai are elementary developments. [Ms T, Adler reports, reads fane/rwsis 'elucidation' in place of fanerw=sai. This makes better sense, but is possibly a copyist's improvised correction.]