1. A method, process, or course of action that is uncommon, rare, or not typically followed
The company implemented an unusual procedure for hiring new employees.
A empresa implementou um procedimento inusual para contratar novos funcionários.
2. A deviation from standard or established protocols
The surgeon had to use an unusual procedure due to the complexity of the case.
O cirurgião teve que usar um procedimento inusual devido à complexidade do caso.