It doesn't have a definition and doesn't need one. It's liberally applied to all forms of "people being offended". It exists in the space between behavior that

It doesn't have a definition and doesn't need one. It's liberally applied to all forms of "people being offended". It exists in the space between behavior that is legal yet morally unacceptable. Like abject racism. The actual quality of offending is purely subjective and always has been. Someone can be considered "cancelled" when a critical mass of people agree and refuse to support them. This is how every society has existed forever.