The headword (not in LSJ), accented thus, is unattested outside grammarians and lexicographers. Of these, Etym. Magn. 484.55-57 expands the present gloss (for which cf. kappa 152) most helpfully: "it means him who is being punished, or badly treated." Another possibility is that we are dealing with a pronunciation-dependent spelling of κακηθός , apparently a rarely attested ([Herodianos] 3.1.146) variant for κακ̔ὀηθής ('base in character'). Note the different accentuation, however.
Also possibly relevant are Hesychius entries s.v. κακιθά (kappa306) κακιθής (kappa307) and κακιθές (kappa308), glossed as "hungry" (cf. LSJ suppl. however), "withered vine" and 'difficult', starving' respectively. See, however, Chantraine s.v. κάγκανος on these terms.