毫厘不爽 háo lí bù shuǎng

DEFINITIONS

  1. not to deviate an iota (idiom)
  2. to be extremely accurate

CHARACTERS

毫 háo fine hair; measure of length
厘 lí manage, control; thousandth part of tael
不 bù no, not; un-; negative prefix
爽 shuǎng happy, cheerful; refreshing