A muscle strain is the stretching or tearing of muscle fibers. Most muscle strains happen for one of two reasons: either the muscle has been stretched beyond its limits or it has been forced to contract too strongly. In mild cases, only a few muscle fibers are stretched or torn, and the muscle remains intact and strong.
Full Definition of HYDROGEN. : a nonmetallic element that is the simplest and lightest of the elements, is normally a colorless odorless highly flammable diatomic gas, and is used especially in synthesis â see element table â compare deuterium, tritium.â hyÂ·drogÂ·eÂ·nous \hÄ«-Ëdrae-ËdrÃ¤-jÉ\ nÉs. adjectiveord History of HYDROGEN. When hydrogen is burned it combines with oxygen to make water. That fact accounts for the name of this gas. The word hydrogen was formed from two Greek roots. The first, hydro- , means â water, â and the second, -gen, means â giving rise to, producing.
LINK / CITE ADD TO WORD LIST. noun. The element hydrogen on the periodic table. The element hydrogen on the periodic table. The definition of hydrogen is a gaseous element that has no color or odor and is flammable. An atom of hydrogen is the smallest of all elements that exist. 2  Hydrogen is the most plentiful element in the universe. 3  An atom of hydrogen is made up of two subatomic particles, one electron and one proton.