3D

3D, 3-D or 3d usually means three-dimensional or three dimensions and may refer to:

Science, technology and mathematics

3D computer graphics, computer graphics that use a three-dimensional representation of geometric data
3D display, a type of information display that conveys depth to the viewer
3D film, a motion picture that gives the illusion of three-dimensional perception
3D modeling, developing a representation of any three-dimensional surface or object
3D printing, making a three-dimensional solid object of a shape from a digital model
3D television, television that conveys depth perception to the viewer
3D projection
3D rendering
3D scanning, making a digital representation of three-dimensional objects
3D video game
Stereoscopy, any technique capable of recording three-dimensional visual information or creating the illusion of depth in an image
Three-dimensional space

Robert Del Naja (born 1965), also known as 3D, English artist and musician in the band Massive Attack
The 3Ds, a rock band

3D Aerobatics, a form of flying using flying aircraft to perform specific aerial maneuvers
3D (Long Island bus), bus service in New York State
3D Test of Antisemitism, put forth by Israeli politician and human rights activist Natan Sharansky
Middle finger, the third digit (abbreviated 3D) of the hand
Three-dimensional chess
Threepence (disambiguation), a coin used in several countries, abbreviated as '3d'
The 3D ("Dudley Death Drop"), a professional wrestling double-team maneuver