The Greek noun diaphthora refers to complete corruption or decay — the physical decomposition of a body. It is derived from diaphtheiro (to destroy thoroughly). In Acts, it becomes a crucial term in Peter's and Paul's arguments for the resurrection of Jesus.
Peter's Pentecost sermon (Acts 2:27, 31) and Paul's sermon at Antioch (Acts 13:34–37) both hinge on Psalm 16:10: 'you will not let your Holy One see corruption (diaphthoran).' The argument is that David died, was buried, and his tomb was known — therefore the Psalm couldn't refer to David, who did see diaphthora. But Jesus, raised on the third day, did not see diaphthora. The resurrection is thus the definitive proof that Jesus is the Holy One — the only human body that escaped the universal law of physical decay, inaugurating the new creation.