What does it mean if a guy calls you a solid 10?

If a guy calls you a solid 10, he is expressing that he finds you extremely attractive or appealing, with a perfect score on a scale of attractiveness. This compliment signifies that he sees you as someone who stands out and possesses qualities he highly admires. It can also indicate that he is interested in you romantically or appreciates you on a deeper level. Overall, it's a positive affirmation of your allure.