- Classical Mythology. a son of Zeus and Europa, rewarded for the justice he exemplified on earth by being made, after his death, a judge in the Underworld, where he served with his brothers Minos and Aeacus.
- an inflexibly just or severe judge.
- Greek myth one of the judges of the dead in the underworld
1580s, from Latinized form of Greek Rhadamanthos, one of the judges of the lower world (son of Zeus and Europa); used allusively of inflexible judges. Related: Rhadamantine.