In turn, taximeter is an adaptation of the French word ‘taximètre’, which is a derivation of the German word ‘taxameter’, coined from Medieval Latin ‘taxa’ which means ‘tax/charge’ together with ‘meter’ from the Greek ‘metron’ meaning measure

http://en.wikipedia.org/wiki/Taxicab

In the 1890s, electric-powered taxicabs took passengers in U.S. and Europe. (& what became of that?!) In 1891, a German, Wilhelm Bruhn, invented the taximeter, which automatically calculated distance or time traveled to determine fare…

…giving rise to the the “taxi” in taxicab.

It’s a little confusing…I think the coaches used in the earlier days were called taxicabs at some point before the taximeter, because the people who took them were charged a fare, a ‘tax,’ so to speak, to ride in the coaches called cabriolet. And that fare was unregulated and so it was probably taxing. So they call the things taxicabs before taximeters began. ;-}

so it’s a cabriolet (some sort of vehicle) that uses a taximeter which measures and indicates how much we pay for when we “hire” one.