See Also:

O(4) (iou)



O noun2 & adjective. Pl. O's, oes. L16.
[from resemblance in shape to the letter O.]
A. noun.
A round thing, as a circle, round spot, etc. L16.
b. In pl. Small circular spangles used to ornament clothing. Only in 17.
The arabic zero, 0; a cipher, a mere nothing. E17.
b. attrib. or as adjective. Designating a gauge of track in model railways (now 32 mm). E20.
Comb.: OO adjective designating a model railway gauge of 16.5 mm. OOO adjective designating a model railway gauge of 10 mm.