A meter or metre is the base unit of length in the International System of Units. It’s basically a measurement/unit
LEDC means that a country is a developing country (as opposed to a developed country). This distinction is connected to the Brandt line which divides the world into developed and developing country, and India is south of this line (=LEDC, less developed country). Some reasons for this is malnutrition, high child mortality and short life expectancy.
Central America refers to the seven states south of Mexico: Belize, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica, and Panama. Panama borders the South American country of Colombia. During the colonial era, Panama was included in the part of South America controlled by the Spanish.
The Boomerang Nebula located 5,000 light years away from our home planet is measured -457.87*F or -272.15*C in temperature. It is believed to be a star system in the constellation Centaurus.