The báidào is the moon's orbital path around the Earth.
Tips
usage
Always paired conceptually with 黑道 (heidao, 'underworld'). 白道 = cops, officials, legitimate business; 黑道 = triads, criminals. The metaphor goes back to white/black as good/evil.
culture
The astronomy sense (moon's path) is much older — Han-dynasty astronomers contrasted 白道 (moon) with 黄道 (huángdào, ecliptic / sun's path).
