autocab is a twentieth-century compound of auto- (from automobile, ultimately Ancient Greek autos 'self') + cab (shortening of cabriolet). Morphologically, the word is transparent as a compound: its parts remain visible in the modern spelling, while the older history of those parts supplies the deeper ancestry. In modern use, the noun sense is "a taxicab, especially one summoned by an automated radio system", which keeps the etymology connected to the word's present dictionary value rather than treating it as a merely historical label. The wider word family includes related English forms such as taxicab, automobile, cab, showing how the same base continues to support neighboring English vocabulary. The principal historical forms in the chain include Ancient Greek autos, which anchor the explanation in named linguistic material.