1. plural of cycloid; curves traced by a point on the circumference of a circle as it rolls along a straight line
Usage: mathematics; geometry
2. plural of cycloid; fish scales that are thin, smooth, and circular with concentric rings
Usage: biology; ichthyology

Examples

• The mathematician studied several cycloids to understand their properties.
• Cycloids appear in physics problems involving rolling wheels.
• The brachistochrone curve is one of the most famous cycloids in mathematics.
• Salmon have cycloids that help identify their age.
• The fish’s cycloids were examined under a microscope.
• Different species of fish can be distinguished by their cycloids.
• Cycloids grow in rings as the fish ages.