Through and through Definition 1 of 3Pro Tip 1/3Emphatic Character Indicates someone's nature or character is completely as described. He's an artist through and through, always seeing the beauty in life. Pro Tip 2/3Beneath the Surface Suggests looking beyond the surface, to the deepest core of a person or thing. Although she appeared stern, she was kind-hearted through and through. Pro Tip 3/3No Doubt Used to express strong agreement or to reassure that the description is accurate. Yes, he is trustworthy through and through; you can rely on him.