The term "re-generation" is commonly used as a reference to the process of creating anew or restoring what was lost. Its antonyms are those words that connote the opposite meaning, such as deterioration, decline, decay, and destruction. Deterioration pertains to the gradual collapse or decline of the quality, performance or value of something. Decline characterizes a steady decrease in quantity or power, and it usually refers to the weakening or decreasing element of something over a period. Decay, on the other hand, signifies a natural process of becoming rotten or corrupt, while destruction refers to the systematic or deliberate destruction or ruin of something.