Definition of insist on/upon
1 : to say or show that one believes that something is necessary or very important My source insisted on anonymity. She insists on doing everything her own way.
2 informal : to continue doing (something that other people think is annoying or unimportant) The people sitting next to us insisted on talking during the entire movie.
Seen and Heard
What made you want to look up insist on/upon? Please tell us where you read or heard it (including the quote, if possible).