The word "沦亡" is formed by combining the character "沦", meaning to sink or decline, often depicted with a water radical to suggest submersion or ruin, with the character "亡", meaning to perish or die. Together, they create a compound where "沦" indicates the process of falling into decay, and "亡" specifies the end state of destruction, resulting in a term that denotes complete downfall or annihilation.