Aureous -eus: gold-colored.
Aurichalceous: brassy yellow.
Auricle -cula: an appendage resembling a little ear; in Odonata the tumescent area at the sides of the second abdominal segment: in Andrenidae, a short membranous process placed laterally on the ligula.
Auricular: applied to the space or cavity surrounding the dorsal vessel.
Auriculate: with an ear-like appendage or, in antennae, with the basal joint distended into a concave, plate-like ear which envelops the rest of the structures.
Auriculo-ventricular: the outer valves of the heart between the auricular space and the chamber.
Auriculo-ventricular openings: are the lateral openings into the heart by means of which the blood is admitted into it.
Auritus: with two ear-like spots or appendages.
Auroral spot: applied to the bright orange colored spot at the apical area of Anthocharis.
Auroreous -eus: red, like the aurora borealis [crimson lake].