Old English feorðing (Old Northumbrian feorðung) "quarter of a penny; a fourth part," a diminutive derivative of feorða "fourth" (from feower "four;" from PIE root *kwetwer- "four") + -ing "fractional part." Cognate with Old Frisian fiardeng, Middle Low German verdink, Old Norse fjorðungr, Old Danish fjerdung "a fourth part of anything."
In late Old English also a division of land, probably originally a quarter of a hide. The modern English coin first was minted under Edward I and abolished 1961. The word was used in biblical translations for Latin quadrans "quarter of a denarius."
I shall geat a fart of a dead man as soone As a farthyng of him. [Heywood, "Proverbs," 1562]