godan verb (-ru), intransitive verb
Intransitive verb for something becoming less in amount, number, size, or intensity. Often used with subjects like 人口, 体重, 量, 数, 痛み, etc.
Antonyms: 増える
最近、体重が減った。
I've lost weight recently.
この町の人口は年々減っている。
The population of this town is decreasing year by year.