A period of time in geology or astronomy characterized by specific events or conditions.

Inflammation or infection of the tissue around the base of the fingernail or toenail.

A cyclic ether with a three-membered ring, commonly involved in chemical reactions such as polymerization or the formation of other organic compounds.

The plane of the cell where chromosomes align during metaphase of cell division, particularly in mitosis and meiosis.

A state in which the concentrations of reactants and products in a chemical reaction remain constant over time, indicating a balance between forward and reverse reactions.

A number that expresses the ratio of the concentrations of products to reactants at equilibrium in a reversible chemical reaction.

An expression that describes the relationship between the concentrations of reactants and products in a chemical equilibrium.

A genus of large, hoofed mammals, including the horse, zebra, and donkey.

A chemical symbol for the element erbium, a rare-earth metal used in various applications such as lasers and optical fibers.

A period of time characterized by particular events, conditions, or developments, often used in geological and historical contexts.