おそらくラテン語のpanna(小皿)から借用したもので、語源的にはpanと同じ、つまり小皿のような形をしている。
Offa's reformed coinage on light, broad flans is likely to have begun c.760-5 in London, with an awareness of developments in Francia and East Anglia. ... The broad flan penny established by Offa remained the principal denomination, with only minor changes, until the fourteenth century. [Anna Gannon, "The Iconography of Early Anglo-Saxon Coinage," Oxford, 2003]The English coin was originally set at one-twelfth of a shilling and was of silver, later copper, then bronze. There are two plural forms: pennies of individual coins, pence collectively. In translations it rendered various foreign coins of small denomination, especially Latin denarius, whence comes its abbreviation d.