‘宿仇’ literally combines ‘宿’ (sù), meaning ‘long-standing,’ ‘deep-rooted,’ or ‘from the past,’ and ‘仇’ (chóu), meaning ‘enemy,’ ‘grudge,’ or ‘bitter hatred.’ Together, they form a noun meaning ‘a long-standing grudge’ — a deep, enduring enmity that has persisted over time, often across generations or years of conflict. It implies more than a simple disagreement; it suggests accumulated resentment, unresolved hostility, and historical tension.

This word is commonly used in formal writing, historical narratives, literature, and dramatic dialogue — especially when describing feuds between families, clans, political factions, or rival groups. It carries a weighty, somewhat literary tone and is rarely used in casual speech. Because ‘宿’ here is pronounced sù (not xiǔ or xiù), learners must pay close attention to tone and context to avoid mispronunciation or confusion with other meanings like ‘to stay overnight.’