1. to become thick or thicker in consistency, density, or width
2. to make something thick or thicker
3. to become more complicated or intense
Usage: figurative

Examples

• The sauce thickens as it cools.
• Add flour to thicken the gravy.
• The fog thickens in the evening.
• The plot thickens when new evidence appears.
• Her accent thickens when she gets excited.
• The crowd thickens near the entrance.
• Blood thickens in cold temperatures.