The Greek adjective azymos means without leaven or yeast (a- + zymē, G2219, leaven). It refers both literally to unleavened bread — the bread of the Passover feast — and metaphorically to a life free from corruption and sin. The Feast of Unleavened Bread (heortē tōn azymōn) immediately followed Passover (Luke 22:1; Acts 12:3). Unleavened bread was a reminder of Israel's hasty departure from Egypt, when there was no time for bread to rise.
Paul uses azymos in one of the most powerful ethical applications in the epistles: Get rid of the old yeast, so that you may be a new unleavened batch — as you really are. For Christ, our Passover lamb, has been sacrificed. Therefore let us keep the Festival, not with the old bread leavened with malice and wickedness, but with the unleavened bread of sincerity and truth (1 Corinthians 5:7–8). The Passover is not just a past event but a present reality — believers are called to live as azymoi, as those purified by the sacrifice of the Lamb. Holiness flows from the Gospel.