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riddle; puzzle; enigma
祖父はいつも面白い謎々を教えてくれた。
My grandfather always taught me fun riddles.
謎々の本を図書館で見つけて借りた。
I found a book of riddles at the library and borrowed it.
簡単な謎々でも子どもたちは大喜びだ。
Even simple riddles make the children very happy.