台Taivo A Taiwan Mandarin dictionary

博士買驢

bóshìmǎilǘ

ㄅㄛˊ ㄕˋ ㄇㄞˇ ㄌㄩˊ

Simplified 博士买驴

1(idiom) to act like the scholar who wrote at length about buying a donkey without even mentioning the word "donkey"; to write at length without ever getting to the point

Keep 博士買驢 and it comes back until you know it.