becoming lower, smaller or weaker 下降：变得更低，更小或更弱 The declining birth rate is common to all developed countries. 出生率下降是所有发达国家的通病。 declining sales/revenues 销售额/收入下降 Declining health forced him to retire from business. 健康状况恶化迫使他从商界退休。
Idioms
somebody’s declining years
- (literary)
the last years of somebody’s life 暮年；晚年