OD

Initialism of overdose.

Initialism of Doctor of Optometry; also O.D.

Initialism of overdrive.

Initialism of overdraft.

Initialism of optical density.

(of a pipe, tube, or shaft) Initialism of outer diameter or outside diameter.

Initialism of olive drab (“color of clothing, uniforms, tools, and equipment”).

Initialism of over dimension, used on route numbers for large vehicles, and normally followed by a numeral, e.g. OD5.

Initialism of organization development.