"one of the common people, a low-born person," 1856 as a colloquial shortening of plebeian in the ancient Roman sense. West Point sense attested by 1851 (see plebe). Related: Plebbish.
Entries linking to pleb
plebeian adj.
"of or characteristic of the lower or the common people," 1560s in a Roman historical sense, from Latin plebeius "belonging to the plebs," earlier plebes, "the populace, the common people" (as opposed to patricians, etc.), also "commonality; the mass, the multitude; the lower class" (from PIE *ple-, from root *pele- (1) "to fill"). In general (non-historical) use from 1580s.
plebe n.
also pleb, "member of the lowest at a U.S. military academy," 1833, probably a shortened form of plebeian "one of the lower class," which in Latin had also the short form plebs or plebes.