The term METRIC TRILLION is composed of two words: 'metric' and 'TRILLION'. The first word, 'metric', refers to the International System of Units (SI), which is a system of measurement used in science, engineering, and commerce. The second word, 'TRILLION', is a number equal to one million million, or 1, 000, 000, 000, 000. Together, the two words form a unit of measurement equal to one million million metric units.