1. a unit of frequency equal to one million cycles per second
Usage: technical; largely replaced by ‘megahertz’

Examples

• The radio station broadcasts at 101.5 megacycles.
• Early electronics manuals used megacycles instead of megahertz.
• The frequency was measured in megacycles per second.
• Modern equipment displays frequencies in megahertz rather than megacycles.
• The transmitter operated at 50 megacycles.
• Scientists converted the megacycle readings to the newer unit system.