1. The primary or most important case in a legal proceeding or investigation
The detective focused on the main case rather than the minor incidents.
O detetive se concentrou no caso principal em vez dos incidentes menores.
2. In grammar, the principal case form of a noun or pronoun used as the base form
In Latin, the nominative is often considered the principal case.
Em latim, o nominativo é frequentemente considerado o caso principal.
3. The most significant or relevant instance in a series of similar situations
This particular case is the principal case we need to address.
Este caso particular é o caso principal que precisamos abordar.