Originally defined as "civil" due to its separation from the military. In the past it denoted all types of engineering including electrical, mechanical, mining, etc. Today it includes bridges, canals, docks, foundations, harbors, off-shore construction, railways, river basin management, sewerage, soil mechanics, structural design, construction, traffic engineering, water supply, etc. The field so large that no engineer can easily specialize in more than two areas.
In other words, civil engineering deals with civilization building and maintenance.
They also like to drink beer, crack lewd jokes, and are generally above average in both looks and intelligence thus guaranteeing that they can attract members of the opposite sex and fill the world with more civil engineers.
Woman 1: Is that a civil engineer over there?
Woman 2: He is devastatingly handsome isn't he?