Why is the ninth month called September?
"agreement," 1590s, from Latin compactum "agreement," noun use of neuter past participle of compacisci "come to agreement," from com- "together" (see com-) + pacisci "to covenant, contract" (see pact).
"make-up case," 1921, from compact (adj.), based on its containing compacted face powder.
early 15c., from Latin compactus, past participle of compingere "to fasten together" (see compact (adj.)). Related: Compacted; compacting.
in mathematics, property of some topological spaces (a generalization of Euclidean space) that has its main use in the study of functions defined on such spaces. An open covering of a space (or set) is a collection of open sets that covers the space; i.e., each point of the space is in some member of the collection. A space is defined as being compact if from each such collection of open sets, a finite number of these sets can be chosen that also cover the space