1. （人、态度、行为）不遵循传统的，异于常人的，标新立异的
If you describe a person or their attitude or behaviour as unconventional, you mean that they do not behave in the same way as most other people in their society.
2. （做事方式）非传统的，不寻常的，非一般的
An unconventional way of doing something is not the usual way of doing it, and may be rather surprising.
1. not conforming to accepted rules or standards
e.g. her unconventional dress and hair style
2. not conventional or conformist
e.g. unconventional life styles
3. not conforming to legality, moral law, or social convention
e.g. an unconventional marriage
improper banking practices