The dictionary's first definition is, "Confident belief in the truth, value, or trustworthiness of a person, idea, or thing." I'm not aware of anyone using that definition. If someone has absolute proof that something is true, they wouldn't say they have faith it's true. It is not one of the three common usages I'm listing here.
The second definition in the dictionary is, "Belief that does not rest on logical proof or material evidence." I do find this to be one of the three ways I hear people use the word 'faith'. As in, "I have faith I'll win the lottery this weekend." It's likely someone will, but there's no reason to believe that it will be you. As unlikely as it seems, people do believe in things without logical proof or material evidence all the time.
The second common usage of the word 'faith' I hear is, Belief based on logical proof or material evidence. As in, "I double checked all the equipment, and have faith we'll have a safe climb up the mountain." We checked the evidence before determining what to believe. This definition is not in the dictionary, but it is common usage.
Let's stop for a moment to analyze that. By my estimation, these are the two most common uses of the word 'faith', and they have the exact opposite meanings. Most people use both, and don't realize there's a distinction. I personally didn't realize the distinction for a long time. Part of the reason is the third usage.
That is, Belief without absolute certainty. You will not find this definition in the dictionary, nor should you. It is used, but not as commonly, and is not useful. The gambler who has faith he's about to win the lottery without any evidence, and the climber who placed his faith in a careful examination of the evidence, are both believing without absolute certainty. Our ticket holder may not win the lottery, and our rock climber may fall to his death when his line breaks. The problem is, we can be certain of almost nothing, and we don't wait for certainty before believing in anything. This definition would apply to just about anything anyone believes, and only leads to confuse matters.