The word database is a composition of "data" and "base". "Data" are facts of the real world, which is supplied by "base". The word "data base" was first used in the beginning of 1960's, then written as "data-base" and recently "database".
There is another word, file, in the meaning of collection of facts of the real world. However, a file is an accumulation of data of the same kind of structure. On the other hand, a database is an integration of different kind of data.