Firmly, often unreasonably immovable in purpose or will
See syn. study at
He became adamant on this point.
John seemed pretty adamant he wasn't in love with her, proclaiming it loudly to anyone who would listen.
The doctors had been absolutely adamant that she wasn't going to get better.
She was adamant that people should know what they are consuming.
People become very adamant about the direction they believe their interests will take them.