1. relating to or denoting the rising or setting of a star at or near the same time as the sun
Usage: astronomy; technical

Examples

• The acronycal rising of Sirius marked an important date in the ancient Egyptian calendar.
• Astronomers observed the acronycal setting of the bright star just before dawn.
• In classical astronomy, acronycal phenomena were used to track seasonal changes.
• The acronycal position of the star made it visible only during specific times of year.