A hair's breadth
Meaning
An extremely small distance or amount, so slight as to be almost imperceptible.
Origin
The phrase 'a hair's breadth' draws its vivid imagery from one of the smallest, most commonly understood units of measurement imaginable: the width of a single human hair. For centuries, before standardized units like millimeters or microns became commonplace, people relied on accessible, everyday objects to describe minuscule distances. A human hair, typically ranging from 17 to 180 micrometers thick, offered a perfect, universally relatable metaphor for something incredibly narrow or almost immeasurable. The phrase captures that feeling of an almost non-existent gap, so close that only the thinnest possible barrier could fit, conveying a sense of extreme precision or a near miss with striking simplicity.
Examples
- The car missed the pedestrian by a hair's breadth, causing everyone on the street to gasp in unison.
- His answer was a hair's breadth from being perfectly accurate, but not quite there for full marks.