The headword is a lengthened form of the genitive singular of ka/rh, an epic word for "head" (see LSJ s.v. ka/ra, A). We find virtually the same gloss in one of the scholia to Nicander, Alexipharmaca 133: karh/atos: kefalh=s. Before the Hellenistic poets, karh/atos occurs only once (Homer, Iliad 23.44: web address 1) but thereafter quite often as an epic intertext (e.g. Theocritus, Apollonius Rhodius, Nonnus).