The definition of "rare" is subjective and depends heavily on the context in which it is used.

Here's a breakdown of how "rare" can be interpreted:

• General Usage: In everyday language, "rare" typically means something not commonly found or seen; something unusual or exceptional.
• Statistical Context: In statistics, a rare event is one with a low probability of occurring. The threshold for what constitutes a "low probability" is often arbitrary and depends on the specific application. For example, in hypothesis testing, a p-value of less than 0.05 (5%) is often considered statistically significant and might be described as rare.
• Specific Fields:
• Medicine: A rare disease is generally defined as a condition that affects a small percentage of the population. In the United States, this is typically defined as affecting fewer than 200,000 people. Source
• Ecology: A rare species is one that has a small population size, a restricted geographic range, or both. Source
• Collectibles: In the world of collectibles (stamps, coins, cards, etc.), rarity is a key factor in determining value. A rare item is one with few known examples, often due to limited production or accidental destruction.

In summary, there's no single, universally accepted definition of "rare." Its meaning is relative and must be understood within its specific context.