こうたい後退koutai
1.
The act of moving backward or away from a previous position, often indicating a step back in progress or direction.
2.
A decline in performance or effectiveness, such as a reduction in success or a weakening of influence.
3.
The process of losing ground in terms of ranking, popularity, or support compared to previous standings.
Example:
自動車の売れ行きは年度末に後退しました。