# Why are compact sets called “compact” in topology?

Given a topological space $X$ and a subset of it $S$, $S$ is compact iff for every open cover of $S$, there is a finite subcover of $S$.

Just curiosity: I've done some search in Internet why compact sets are called compact, but it doesn't contain any good result. For someone with no knowledge of the topology, Facing compactness creates the mentality that a compact set is a compressed set!

Does anyone know or have any information on the question?

• Maybe you can try looking up a dictionary - the definition of compact. I personally like Google's definition: closely and neatly packed together. – ireallydonknow Jan 4 '14 at 16:21
• Actually, I think "compact" is one of the best names for a concept in mathematics. The word really captures the intuitive feel of this fairly abstract definition quite well. (Really, the only other word I can think of that does so much conceptual legwork is "smooth".) – Jim Belk Jan 4 '14 at 18:53