Phthartos describes what is subject to passing away, contrasted in these verses with what is incorruptible or imperishable.

The term consistently marks persons or things as subject to passing away: human mortality in contrast with incorruption, a prize crown, material wealth, seed, and the human likeness used for an image. Each occurrence is set against something described in the verse as incorruptible or imperishable, either explicitly or by contrast.

1. Subject to passing away · dominant

   In 1 Corinthians 15:53 and 1 Corinthians 15:54, the neuter singular form identifies what must put on incorruption and immortality; the APB renders the clause "this perishable must put on incorruption." The same characterization applies to a crown in 1 Corinthians 9:25, to silver and gold in 1 Peter 1:18, to seed in 1 Peter 1:23, and to a human likeness in Romans 1:23; each verse contrasts the described item with what its clause presents as incorruptible or imperishable.

   1 Corinthians 15:531 Corinthians 15:541 Corinthians 9:251 Peter 1:181 Peter 1:23Romans 1:23

In the Anselm Project Bible: Across all six verses, the APB uses "perishable" for the relevant contrast: a body, crown, things such as silver or gold, seed, and a human. These renderings confirm the recurring verse-level contrast with "incorruption," "incorruptible," or "imperishable," but the translation does not mark word-by-word correspondence.