koan
Concise Oxford English Dictionary © 2008 Oxford University Press:
koan /ˈkəʊɑːn, ˈkəʊan/
▶noun a paradoxical anecdote or riddle, used in Zen Buddhism to show the inadequacy of logical reasoning and provoke enlightenment.
– origin Japanese, lit. ‘matter for public thought’, from Chin. gōngàn ‘official business’.
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