When someone says, "I'm not hairy," they are most likely referring to the amount of hair on their body. It means that they don't have a significant or noticeable amount of body hair, or they may have less body hair compared to other people.
Body hair is a natural characteristic that varies from person to person and is influenced by genetics, hormones, and other factors. Some individuals may have more body hair, while others may have very little, making them describe themselves as "not hairy."
The context in which someone makes this statement can vary. It could be a casual remark about their physical appearance or a topic of conversation related to body image or self-confidence.