and/or

and/or

A conjunction indicating an option or possibility of both things listed ("and") or either thing listed ("or"). Come on, we need to celebrate a little bit! Can't we at least have cake and/or ice cream in honor of your birthday?
See also: and
Farlex Dictionary of Idioms.

and/or

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.
See also: and
The American Heritage® Dictionary of Idioms by Christine Ammer.
See also:
  • can't
  • all of the above
  • and all this
  • and things
  • and things (like that)
  • have letters after (one's) name
  • nilly