What is a happy trail?

A "happy trail" is a colloquial term for a line of hair extending from the navel down towards the pubic area. It's often, but not always, sparsely populated with hair. The term is playful and generally used in a lighthearted way. There's no real significance to it beyond the descriptive nature of its appearance. Some people embrace it as part of their natural body hair, while others choose to remove it through shaving, waxing, or other methods. Essentially, it's just a fun name for a specific body hair pattern.