1. In music theory, a sharp or flat that is not part of the key signature and appears in a musical score to modify the pitch of a note
The composer used an accidental plane to create a chromatic passage.
O compositor usou um plano acidental para criar uma passagem cromática.
2. In geometry, a plane that occurs or appears by chance or without planning
The accidental plane formed by the intersection of the two surfaces was unexpected.
O plano acidental formado pela intersecção das duas superfícies foi inesperado.