Koan

A kōan (公案) (/ˈkoʊ.ɑːn/; Chinese: 公案; pinyin: gōng'àn, [kʊ́ŋ ân]; Korean: 공안 kong'an; Vietnamese: công án) is a story, dialogue, question, or statement, which is used in Zen practice to provoke the "great doubt" and test a student's progress in Zen practice.