I was speaking to a young woman the other day who told me she was a member of a citywide youth commission on “equity” and “solidarity.” When I asked her what that meant, she seemed startled. Some words are designed to be conversation stoppers. If someone is an “activist,” or fighting for “human rights” or “inclusion,” if she believes in “diversity” or wants to “change the world,” we are all supposed to understand the meaning and the mission.