To profess means to declare or claim something openly, especially a belief, feeling, or area of knowledge. When someone professes their love for baseball, they're stating it clearly and publicly. When a scientist professes expertise in marine biology, she's declaring that as her field of knowledge.

The word often carries a sense of seriousness or formality. You might say you like pizza, but you'd profess your dedication to becoming a better writer. Teachers are called professors because they profess (declare and demonstrate) their knowledge of a subject to students.

Sometimes people profess things they don't truly believe or intend to follow through on. A student might profess interest in joining the chess club but never actually show up. When someone's actions don't match what they profess, we might say they don't practice what they preach.

When you profess something, you're putting your reputation on the line behind your words.