Something that is noticeable is apparent or easy to be noticed. If the change in your report cards is noticeable, let's hope it’s because your grades went up!
It’s easy to remember noticeable, by thinking of it as able to be noticed. Noticeable also means deserving of being noticed, or notable, like good manners or good work habits. Other noticeable things are just easy to spot, and not always in a good way. That piece of spinach between your teeth the entire time you were having lunch with your boss? “Don’t worry; it was hardly noticeable."