星宿

The 宿 here is read xiù (fourth tone) — the astronomical reading meaning 'lunar mansion' — not sù ('lodge') or xiǔ ('night classifier'). Three readings for one character, all alive in modern Chinese.

culture

The twenty-eight 宿 divide the sky into four quadrants (azure dragon east, white tiger west, vermilion bird south, black tortoise north), each with seven mansions. The system was used for both astronomy and astrology, including determining auspicious dates.