Source : CEDICT

lit. three humble visits to a thatched cottage/cf famous episode in the fictional Romance of Three Kingdoms 三國演義|三国演义 in which Liu Bei 劉備|刘备 recruits Zhuge Liang 諸葛亮|诸葛亮 (the Hidden Dragon 臥龍|卧龙) to his cause by visiting him three times