The Greek verb aponiptomai means to wash off, to rinse away, or to wash clean. The middle voice form (aponiptomai) indicates washing oneself or washing something off oneself. The word combines apo- (off/away) and nipto (to wash). Its most famous New Testament occurrence is Pilate's act of washing his hands.
The single most theologically significant use of aponiptomai is Matthew 27:24, where Pilate 'washed his hands' before the crowd and declared himself innocent of Jesus' blood. The gesture echoed the Old Testament ritual of handwashing to declare innocence (Deuteronomy 21:6-9), but Pilate's act was tragically futile — the attempt to wash off guilt for condemning the Son of God was symbolic and self-deceiving. No external ritual can cleanse a guilty conscience. The only washing that truly removes guilt is the blood of Christ (Revelation 1:5; 1 John 1:7).