The Greek adjective palaios (παλαιός) means old in the sense of ancient, former, or worn out with age. It is used for old wine, old garments, the old covenant, and the old self. It contrasts with neos (new in time) and kainos (new in quality or character). Palaios often carries a sense of what belongs to the former age and has been superseded.
Paul's use of palaios for the 'old self' (palaios anthrōpos) is theologically profound. Romans 6:6 — 'our old self was crucified with him' — declares that the former sin-dominated self died with Christ. This is not gradual improvement but death and resurrection. The contrast between old and new covenant (2 Corinthians 3) uses related concepts: the old glory, though real, pales beside the new. Jesus's parable of new wine in old wineskins (Matthew 9:17) warns against trying to contain the new reality of the Kingdom in old religious structures that cannot accommodate its transforming power.