treasure trail
noun1
Slang A vertical line of hair that extends up along the middle of a person's (usually a man's) abdomen from pubic hair to navel.
- As he says good-bye, he puts both arms over his head and stretches big, causing his shirt to lift up a few inches, exposing the sexiest abs and treasure trail I've ever seen.2006, Karyn Bosnak, 20 Times a Lady, Harper, →ISBN, page 73: