Of unclear origin. Many regard the forms without the medial *-t- or *-d-* as the older ones because the Slavic and Lithuanian loans (Proto-Slavic *pěnędzь) do not show the reflex of a medial obstruent, which makes it difficult to connect with *pandan- (“pledge”) (Old High German phant) or their Latin etymon pondus (“weight”). The second part of the word is probably *-ingaz. The first part is possibly a borrowing of one of these Latin words:
- panna (“pan”), with a semantic shift explained as a penny being a "coin with a concave form" (per De Vries/De Tollenaere), or
- pannus (“piece of cloth”), because cloth was often used as means of payment.
Vennemann suggests another possibility: that *paning may derive from Carthaginian traders' jargon use of Punic 𐤐𐤍 (pn, pane, “face”) to mean "coin", as almost all Carthaginian coins depicted the face of Tanit (a goddess who was herself known as the "face of Baal"), and even the second-most common motif was the face of Melqart; Vennemann further speculates that the variants *panning and *panding preserved the bimoric nature of the Punic word.
*panningaz, *pandingaz, *pantingaz m
- Old English: pending, penning, pæning, pening, pænig, penig
- Old Frisian: panning, penning, pennig
- Old Saxon: penning, pennig
- Old Dutch: *penning
- Old High German: pfending, pfanting, pfenting, phantinc, pfentinc, pfenning
- Old Norse: penningr; pengr (late)
- → Proto-Slavic: *pěnędzь (see there for further descendants)
- Vasmer, Max (1964–1973), “пенязь”, in Etimologičeskij slovarʹ russkovo jazyka [Etymological Dictionary of the Russian Language] (in Russian), translated from German and supplemented by Trubačev O. N., Moscow: Progress
- Saskia Pronk-Tiethoff (2013), The Germanic loanwords in Proto-Slavic, Rodopi: Amsterdam/New York, page 91f