- (used to imply that either or both of the things mentioned may be affected or involved): insurance covering fire and/or wind damage.
- (coordinating) used to join terms when either one or the other or both is indicatedpassports and/or other means of identification
Both or either of two options. For example, His use of copyrighted material shows that the writer is careless and/or dishonest. This idiom originated in legal terminology of the mid-1800s.