Last name Cilium (Cil 
, Seel 
, Cilium) , all over the world, is a common family name. The surname Cilium is characteristic of Germany, where it is quite a rare surname, Austria, and Cyprus. Not in comparison with a country's population, it is the most numerous in Germany, the United States, and Indonesia. Much less frequently, Cilium is the forename as well as the last name.