plebs.

From Old Latin plēbēs and ultimately from the root *pleh₁- (“fill”), though the exact development of the term is unclear. * According to Schrijver, the term derives from the same pre-form as Ancient Greek πληθύς (plēthús), which Schrijver derives from a hysterodynamic form *pléh₁dʰuh₁(s) (acc sg, *pl̥h₁dʰwéh₁m̥; gen sg, *pl̥h₁dʰuh₁ós). Schrijver suggests that Proto-Italic outcome of this sequence was *plēðūs, *plēðēm, *plēðes, wherein the oblique forms were generalized from the PIE accusative singular form. Ultimately, the inflectional pattern of such a form would be synchronically irregular, perhaps leading to a remodeling. The term was reshaped into a fifth-declension form on the basis of the accusative singular *plēðēm, just as diēs was created on the model of diēm. * Kortlandt, however, argues that Proto-Indo-European *-dʰw- would evolve into Latin -b-, whereas intervocalic *-dʰ- yields Latin -d- (e.g. Latin vidua < Proto-Indo-European *h₁widʰéwh₂). Thus, Kortlandt reconstructs an original proterodynamic paradigm. De Vaan reconstructs Proto-Italic *plēðū- ~ *plēðw-, itself from Proto-Indo-European *pléh₁dʰ-uh₁- (acc sg, *-uh₁m̥; gen sg, *-weh₁s). * The linguist Dariusz Piwowarczyk reconstructs an original u-stem *pleh₁dʰ-us ~ *pleh₁dʰwe/os, the oblique stem of which yielded plēbis, whence the nominative singulars plēbs and plēbēs emerged via back-formation. Piwowarczyk further suggests possible contamination from pūbēs. Cognate with Oscan 𐌐𐌋𐌝𐌚𐌓𐌉𐌊𐌔 (plífriks, “plebeian”, nom. sg.), perhaps derived from Proto-Italic *plēðros (adjective). It is also possibly related to Venetic 𐌐𐌋𐌄𐌃⸱𐌄⸱𐌉 (pled⸱e⸱i). See also Latin populus and the Greek-origin borrowing plēthōra.