Whats a metric? A metric century? A metric marathon?
The noun “metric” refers to a measurement for comparing or evaluating something. For example, two metrics for baseball players are the batting average and RBI (runs batted in). A metric (albeit not very useful) for comparing computer programmers is the number of lines of code written each day. A metric for students is the grade or grade point average. Similarly, the Environmental Protection Agency (EPA) needs a metric for comparing fuel efficiency of cars. They’ve considered two metrics, the number of miles per gallon and, as an alternative, a fuel consumption metric in gallons per hundred miles or liters per hundred kilometers. Existing law requires them to include the former on fuel economy labels, so that’s the metric Americans are familiar with. Note that “metric” (in the context of the SI) is an adjective, not a noun: metric system, metric units, metric legislation, metric conversion, metric ton, etc.
