"Define The Great Line" is the second studio album by the American rock band Underoath, released in 2006. The album features a blend of post-hardcore and metalcore elements, showcasing the band's signature sound characterized by intense vocals, intricate guitar work, and dynamic rhythms. It received critical acclaim for its emotional depth and musical complexity. The album's themes explore struggles with faith, personal turmoil, and the search for meaning. Notable tracks include "Writing on the Walls" and "A Moment Suspended in Time," which highlight the band's ability to convey powerful messages through their music. "Define The Great Line" solidified Underoath's place in the post-hardcore scene.