了如指掌 liǎorúzhǐzhǎng know thoroughly Origin Definitions Defs Strokes Stroke Words Sentences Sents 1 sentence 他对这里的地形了如指掌。 tā duì zhèlǐ de dìxíng liǎorúzhǐzhǎng. He knows the terrain here like the back of his hand. Source: Dong Chinese Dictionary