from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A coin containing a minting error.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A coin that is defective, having been incorrectly minted, often prized by collectors.
f(reaks), i(rregulars), d(efects), o(ddities).(American Heritage® Dictionary of the English Language, Fourth Edition)
An acronym made up of the words freaks, irregulars, defects and oddities, from 1960's. (Wiktionary)