Also known as: od.
OD has various meanings in the Scientific & Educational category. Discover the full forms, definitions, and usage contexts of OD in Scientific & Educational.
A property of a transparent material that is a measure of the speed of light through it. Optical density is the density which has no units.
Scientific & EducationalLevel to which heights and depths are referred in English surveying Formerly, the level was a rather inaccurate approximation of mean sea-level at Liverpool Is now mean sea level at Newlyn, Cornwall
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