一丝不苟

Pronunciation: yī sī bù gǒu Literal meaning: Not careless by a single thread

Origin & Usage

Not letting a single (一) thread (丝) be done carelessly (不苟). The thread is a unit of measurement rather than a reference to weaving — on the old scale ten 丝 make one 毫, and 丝 itself divides into ten 忽 — so the claim is about the fineness at which the care operates, not about textiles. Late-imperial vernacular fiction applies it to conduct and paperwork. It is unambiguous praise for accountants, editors, surgeons and anyone whose work is judged by what is not wrong with it, and it is the standard phrase in a reference letter.

Examples

English: "The surgeon performed each procedure with absolute precision"

Chinese: 外科医生一丝不苟地执行每个手术程序