Apekdysis is the noun form of apekdyomai (G554), meaning a complete stripping off, removal, or divestiture. In Colossians 2:11, Paul uses it to describe the "circumcision of Christ" — the complete removal of the body of flesh accomplished in spiritual union with Christ, making physical circumcision irrelevant.
Paul's use of apekdysis in Colossians 2:11 redefines circumcision entirely. The true circumcision is not a physical rite but a spiritual reality — the complete stripping away of the sinful nature through union with Christ's death and resurrection. This is not something the believer achieves but something done by Christ. The old self has been definitively removed.