Following the election defeat, several senior ministers were expected to step down.

step 的基本意思是"迈步、行走"，在这里引申为"采取行动"。 down 的意思是"向下"，在短语中表示"离开职位"或"降低身份"。 step down 是一个固定短语，意思是"辞职"或"下台"，通常指自愿或被迫离开高级职位。