This is the 68th most frequent Indonesian word.
kasus
"Kasus" in Indonesian means "case" (as in an instance, situation, or grammatical case).
Here, 'kasus' means 'case' in the context of an investigation or legal matter.
Kasus tersebut sedang diselidiki oleh polisi.
That case is being investigated by the police.
Here, 'kasus' is used to mean 'cases' in a medical or epidemiological context.
Ada peningkatan drastis dalam jumlah kasus COVID-19 di kota itu.
There has been a drastic increase in the number of COVID-19 cases in the city.
In this context, 'kasus' refers to grammatical 'cases', as used in linguistics.