1. A path, direction, or sequence of events that is uncommon, unexpected, or different from the normal or standard way
The project took an unusual course when the team discovered a new approach.
O projeto seguiu um curso inusitado quando a equipe descobriu uma nova abordagem.
2. An educational program or class that is not typically offered or is unconventional in nature
She enrolled in an unusual course on contemporary art history.
Ela se matriculou em um curso inusitado de história da arte contemporânea.