The Greek word analusis (G359) literally means an unloosing or dissolving — the releasing of something from its bonds. In the New Testament it appears once in 2 Timothy 4:6, where Paul writes: "The time of my departure [analusis] is at hand."
The metaphor draws from multiple images: the loosing of a ship from its moorings to sail, the striking of a tent/camp to move on, or the unharnessing of a beast of burden at the end of the day's work.
Paul's use of analusis for his impending execution is one of Scripture's most serene references to death. Written from a Roman prison, facing execution, he speaks of death not as a catastrophe but as a departure — the loosing of moorings, the freedom to sail toward the destination for which he had been made.
The full context (2 Timothy 4:6-8) frames this analusis as the completion of a race and a fight, followed by "the crown of righteousness." Death for Paul was not annihilation but translation — the final departure into the presence of the Lord he had served. Philippians 1:23 uses the related verb analusai with the same imagery: "I desire to depart and be with Christ, which is better by far."