Definition: A very large city that has a population of millions of people and often serves as a major economic, political, and cultural center.

Example: Tokyo is considered one of the largest megacities in the world.

Definition: A term used to describe one million deaths, often in the context of nuclear warfare.

Example: The nuclear explosion resulted in a megadeath, highlighting the devastating impact of such weapons.

Definition: Large animals that are part of a specific region or time period, often including species like mammoths and bison.

Example: The discovery of ancient megafauna fossils has provided insight into the ecosystems of the past.

Definition: A measure of explosive power that is equal to the energy released by one million tons of TNT.

Example: The bomb had a power of ten megatons, making it one of the most powerful ever created.

Definition: The amount of explosive power that a bomb or a group of bombs can produce, measured in megatons.

Example: The megatonnage of the nuclear arsenal was a major concern for global security.

Definition: Water that comes from the melting of snow or ice.

Example: In spring, the meltwater from the mountains flows into the rivers.

Definition: Relating to an environment that has a moderate amount of moisture, often found in certain types of ecosystems.

Example: The mesic conditions of the forest support a diverse range of plant species.

Definition: The upper boundary of the atmosphere where the temperature is at its lowest point.

Example: The mesopause is located between the mesosphere and the thermosphere.

Definition: Having a moderate level of nutrients and minerals in a body of water, which supports a balanced ecosystem.

Example: The lake is considered mesotrophic because it has a healthy amount of nutrients for aquatic life.

Definition: Made of metal or having metal parts, often used to describe surfaces that are covered with metal or have metal fittings.

Example: The metalled road was smooth and easy to drive on.

Definition: To cover a surface with metal or to make something into metal.

Example: The road was metalled to improve its durability and safety.