| AR | information known only to a special group |
|---|---|
| AR | a measure for arcs and angles |
| AR | (architecture) forming or resembling an arch |
| AR | an amoeba-like protozoan with a chitinous shell resembling an umbrella |
| AR | soil and freshwater protozoa |
| AR | genus of chiefly American plants parasitic on conifers |
| AR | small herb with scalelike leaves on reddish-brown stems and berrylike fruits |
| AR | (architecture) a masonry construction (usually curved) for spanning an opening and supporting the weight above it |
| AR | a passageway under an arch |
| AR | a curved bony structure supporting or enclosing organs (especially arches of the feet) |
| AR | a curved shape in the vertical plane that spans an opening |
| AR | form an arch |