The adjective khka/s is used in Callimachus fr. 656 khka/di su\n glw/ssh| "with an abusive tongue", and Nicander, Alexipharmaca 185 piote/rhn o(/te bo/trun e)si/nato khka\s a)lw/phc "when the mischievous fox plundered the fat grapes". The noun khkasmo/s comes from Lycophron Alexandra 545 (dative plural) or 692 (accusative singular).
Otherwise the words only occur in lexica and scholia: khka/s from Hesychius kappa2482 on; khkasmo/s in e.g. the scholia to Lycophron 545 (above). The Etymologicum Parvum and Etymologicum Magnum derive khka/s from kako/s, a derivation the LSJ repeats with reservations. The Etymologicum Parvum is the first lexicon to gloss khka/s as loidori/a. The word is absent from Photius' Lexicon.