A quick study on the origin of words:
all derived from 'common '
1297, from O.Fr. comun, from L. communis "in common, public, general, shared by all or many," from PIE *ko-moin-i- "held in common,"
PIE: Proto-Indo-European, the hypothetical reconstructed ancestral language of the Indo-European family. The time scale is much debated, but the most recent date proposed for it is about 5,500 years ago.