OhmThe basic unit of electrical resistance equal to one volt divided by one ampere, often usd to measure conductivity. The Conductivity is proportional to the reciprocal of its resistance.
Oligodynamic(Greek: oligos = few, dynamis = force) the great power exerted by certain metals in low concentration, an effect discovered by Swiss Botanist Karl Wilhelm von Nägeli in 1893.
OralA route of administration meaning to be taken by mouth.
Organic, Organic moleculeSubstance whose molecules contain one or more carbon atoms (often many more than one, but excluding carbonates, bicarbonates, cyanides, carbides, and a few others). Until 1828, scientists believed organic compounds could be formed only by life processes. Carbon is more likely to form molecular chains and rings than elements do, so its compounds are vastly better known than all others.
OxidationThe loss of electrons by an Atom or molecule; the gaining of oxygen by a substance and the resulting chemical effect and/or surface changes. Opposite of Reduction.
Off-Labelthe prescription or use of a drug or other product other than that for which it has been officially indicated or approved.