1 Hydrogen is the most abundant element in the universe. 2  Hydrogen isn't common in a pure form on Earth, but is mostly found as part of water. 3  Hydrogen is the main fuel of stars and the only fuel for red dwarfs. 4  The whole universe is thought to have been formed by a Hydrogen nucleus.
Noun. 1. hindlimb-a posterior appendage such as a leg or the homologous structure in other animals. hind limb. hind leg-the back limb of a quadruped. limb-one of the jointed appendages of an animal used for locomotion or grasping: arm; leg; wing; flipper. 1  Facebook.
hindbrain structure responsible for automatic body functions such as breathing and heartbeat. part of the hindbrain where nerves cross from one side of the body to the opposite side of the brain; forms the lowest part of the brain; responsible for life-sustaining functions such as breathing, swallowing, and heart rate.