D- means: * Placed before a

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its so ...

, usually in parentheses, indicates the person it applies to is a Democratic Party politician of that state. "R-" is used for the Republican Party. * An academic grade given by certain institutions. Slightly better than an F and slightly worse than a D. See

Grading in education Grading in education is the application of standardized Measurement, measurements to evaluate different levels of student achievement in a course. Grades can be expressed as letters (usually A to F), as a range (for example, 1 to 6), percentage ...

. * A prefix signifying

chirality Chirality () is a property of asymmetry important in several branches of science. The word ''chirality'' is derived from the Greek (''kheir''), "hand", a familiar chiral object. An object or a system is ''chiral'' if it is distinguishable fro ...

of a molecule

See also