Two different Roman brass coins are translated by this word: one of these, the assarion, Matthew 10:29 Luke 12:6, was worth less than a cent; the other, the kodrantes, Matthew 5:26, was probably nearly four mills.
Source: ATS Bible Dictionary
Farthing
Matthew 10:29; Luke 12:6. Greek assarion, i.e., a small
As , which was a Roman coin equal to a tenth of a denarius or drachma, nearly equal to a halfpenny of our money.
Matthew 5:26; Mark 12:42 (Gr. kodrantes), the quadrant, the fourth of an
As , equal to two lepta, mites. The lepton (mite) was the very smallest copper coin.
Source: Easton's Bible Dictionary
Farthing
F'ARTHING, n.
1. The fourth of a penny; a small copper coin of Great Britain, being the fourth of a penny in value. In America we have no coin of this kind. We however use the word to denote the fourth part of a penny in value, but the penny is of different value from the English penny, and different in different states. It is becoming obsolete, with the old denominations of money.
2. Farthings, in the plural, copper coin.
3. Very small price or value. It is not worth a farthing, that is, it is of very little worth, or worth nothing.
4. A division of land. Not now used.
Thirty acres make a farthing-land; nine farthings a Cornish acre; and four Cornish acres a knight's fee.
Source: King James Dictionary
Farthing
Two names of coins in the New Testament are rendered in the Authorized Version by this word:
Quadrans , (Matthew 5:26; Mark 12:42) a coin current in the time of our Lord, equivalent to three-eights of a cent;
The assarion , equal to one cent and a half, (Matthew 10:29; Luke 12:6)