noun
decline; downward tendency; decay
Refers to a waning of power, influence, or vitality; often used in formal or written contexts about nations, organizations, or trends.
その国の衰勢は誰の目にも明らかだった。
The decline of that country was obvious to everyone.
会社の衰勢を食い止めるために、新しい戦略が必要だ。
A new strategy is needed to halt the company's downward trend.