Something that's obliterated is gone. If your dreams of becoming a trapeze artist are completely obliterated after your first two difficult weeks at circus school, maybe you can switch to clowning.
Obliterated comes from the Latin phrase literas scribere, meaning strike or cross out letters. When something is obliterated, it disappears or is so damaged, you can barely recognize it. It might be literally wiped out, like a house obliterated by fire, or figuratively destroyed, like your obliterated hopes of marrying your favorite movie star someday.