Bilious describes a feeling of queasiness or nausea, like your stomach is churning and you might throw up. After eating too much candy at a carnival, you might feel bilious on the spinning teacup ride.

The word also describes someone who is irritable, grumpy, and unpleasant to be around. A bilious person complains constantly and seems angry at everything. Think of a character in a story who snaps at everyone, finds fault with everything, and spreads negativity wherever they go. You might say a teacher gave a bilious response to a student's innocent question if they answered with unexpected harshness.

When describing colors, bilious means a sickly yellowish-green shade, like the color of someone's face when they're about to be sick. A room painted bilious green would look unpleasant and unhealthy, the kind of color that makes you want to leave quickly.

All these meanings share the sense of something unpleasant and uncomfortable, whether it's physical sickness, emotional sourness, or ugly coloring.