precession/prɪˈseʃn; prɪ`sɛʃən/ n[U](also pre,cessionof the `equinoxes) gradual change in the angle at which the earth revolves daily, causing the equinoxes to occur slightly earlier in each successive year 岁差（地球自转角度的渐次变化, 使每年的春分点及秋分点比上年略为提前）.
牛津英汉双解词典