Greece (ISO and NATO country code GR)

General relativity, the geometrical theory of gravitation proposed by Albert Einstein

Grand Rapids, MI, a city in western Michigan

Gwoyeu Romatzyh, a system of romanization for Chinese

Glucocorticoid receptor, a ligand-activated intracytoplasmatic transcription factor

Game-Revolution, a video game review web site

Graubünden, a canton of Switzerland

.gr, the Internet country code top-level domain for Greece

Gabriel Richard High School, a private high school in Michigan

Aurigny Air Services IATA airline designator

Globalise Resistance, a UK anti-capitalist group

GR footpaths, long-distance footpaths in western Europe

Gemini Air Cargo IATA airline designator

Good Riddance, a punk rock band from Santa Cruz, California

Grain (measure) (gr), a unit of mass

Grashof number (Gr) in physics

Graphics Resolution, a graphics mode for Apple II-family computers

Google Reader, a RSS reader service from Google