The only free and comprehensive online etymological dictionary of the Spanish language
cabello m. (Noun) "hair"
11th cent. From Latin capilla 'id.' Of unknown origin. Possibly from a non-Indo-European language with a root *kap- (see cabo).
Also the origin of the surname Cabellos.
Indo-European
Romance
Asturian cabellu, Portuguese cabelo, Galician cabelo, Catalan cabell, French cheveu, Italian capello