The word "Funambulist" is derived from a combination of the Latin root words of funis (rope) and ambulare (to walk). And, yes, the ancient Romans actually did have tightrope walkers; it was a popular art for acrobats and street performers, as it still is today.

The word can also be used in a figurative sense, to describe someone who is mentally agile, or who is able to walk a fine line between two opposing viewpoints (for instance, a slick politician).

source: world wide words (