OD

OD or Od may refer to:

Education

OD or o.d., an abbreviation used in medical prescriptions for omne in die or "once daily" both meaning "take once every day"
Doctor of Optometry (O.D.)
Oculus dexter, ocular dexter, or ocularis dexter, meaning "right eye" in general ophthalmologic or optometric usage, particularly in eyeglass prescriptions
Osteochondritis dissecans, a medical disease affecting the joints of both humans and animals
Overdose, the inadvertent drug effects of the user rendered unresponsive or fatally succumbed due to unsophistication of self-medicating being unaccustomed to quantities greater than recommended

Optical density
Outside diameter (also: O.D.), cylinder or pipe external diameter
Ordnance datum, in Britain, an Ordnance Survey data point
od (Unix), a Unix program
Object Desktop, a suite of skinning and customization programs by Stardock, or ObjectDock, another program by the same company
Optical disc
Organization development, the study of organizational change and performance
Ordinal definable set, a set requiring only finitely-many ordinals to define under first-order logic.

OD (video game), an upcoming video game developed by Kojima Productions and published by Xbox Game Studios
Od language, an Indo-Aryan language of Pakistan
Odic force or Od, a life force
Occupation Double, a Quebec reality show that started in 2003
Official Declaration, part of Latter-day Saint scripture
Olive drab, a color, particularly of some United States Army uniforms
Online dating
Original dance, the second part of an ice dancing competition
Order of Distinction, a civil honour of Jamaica
OD - original designation in Taxonomy