The song "Lionheart (Fearless)" by Joel Corry and Tom Grennan is about being brave and fearless like a lion. The lyrics describe the desire to wake up like a giant and know what it feels like to have the courage of a lion. Despite feeling emotional and searching for a sign, the singer feels a fire burning within them, reminiscent of the stars that illuminate the sky. They feel fearless like a lion, with the strength to face any challenges. Overall, the song encourages listeners to be courageous and face their fears with a brave heart, just like the mighty lion.