1. a confident and forceful statement of fact or belief
2. the action of asserting something

Examples

• Her assertion that the project would fail proved to be correct.
• The lawyer made several bold assertions during his opening statement.
• His assertion of innocence was met with skepticism.
• The scientist’s assertion challenged the accepted theory.
• The assertion of constitutional rights is fundamental to democracy.
• Without evidence, his assertion remained unproven.
• The CEO’s assertion about company profits was later disputed.