The headword adjective is first attested in a fragment of hexameter poetry attributed to Hesiod (fr. 372 Merkelbach-West, in Athenaeus, Deipnosophists 3.116A [3.84 Kaibel]): "ill-clad fisherfolk"
In Hesychius s.v. the (singular) headword is glossed with a)kth/mwn, "possession-less".
Wearing only an i(ma/tion without a xi/twn (an undergarment) out of doors was generally considered inelegant. Individuals described as a)nupo/dhtos kai\ a)xi/twn, "barefoot and tunic-less", are displaying a principled austerity: Socrates in Xenophon, Agesilaus in Aelian, Cato Minor in Plutarch, Gelon in Diogenes Laertius. And note especially the case of Diogenes of Sinope (delta 1141, delta 1143, delta 1144, delta 1145), who according to Aelian, Varia Historia 3.39 used to apply to himself the tragic epithets (TrGF adespota 284) "wandering, homeless, deprived of motherland, beggar, ill-clad, living from one day to the next".