Both words describe a person or thing widely known and (usually) admired. Famous can be applied to anything widely known or “heard of” by many: it most frequently describes actors, artists, and writers and other popular figures. Famous can sound a little shallow and incongruous when used to describe people known and admired for serious accomplishments or contributions. This creates an opening for renowned, which suggests being held in high esteem and celebrated by many, and is usually used for what could be considered more serious accomplishments. You’ll find it used of actors, artists, and writers, but also of experts, architects, professors, economists—and other professions whose expertise is not given a great deal of notice in popular or mass culture.
Both verbs refer to keeping something from happening. Prevent, the more neutral of the two, suggests keeping something from even starting, or employing measures in advance to do so: prevent forest fires. Thwart, which comes from the Old Norse word meaning “across” or “traverse,” suggests a more dramatic interruption of something in process—especially someone’s efforts or plans—before it can reach its goal: thwarted the plot; thwart an alien invasion.
Both nouns refer to the phenomenon or experience of being naturally drawn to a person, thing, or idea. Attraction suggests a desire to get closer to the object, which, for things and ideas, may mean acquiring, adopting, or studying the object. Because talking about an attraction to a person is usually taken to mean a romantic or sexual interest, it’s useful to have affinity at your disposal. Affinity suggests a phenomenon in which a person feels a natural liking toward another person or thing, often based on a recognition of similarity or empathy with them. If a student demonstrates an affinity for lab research, they’re not only interested in it but well-suited to it, and take to it fairly quickly. Someone might possess an affinity with a foreign culture if they have already formed a set of interests and sympathies that are a natural fit.