dimensionless

To Heav'n thir prayers / Flew up, nor miſsd the way, by envious windes / Blow'n vagabond or fruſtrate: in they paſsd / Dimentionleſs through Heav'nly dores; […]

1674, John Milton, “Book XI”, in Paradise Lost. […], 2nd edition, London: […] S[amuel] Simmons […], →OCLC, page 286

1930, E. E. Smith, Skylark Three, Fantasy Press, 1948, Chapter 3, They saw the utter, absolute darkness of the complete absence of all light; and upon that indescribable blackness they beheld superimposed the almost unbearable brilliance of enormous suns concentrated into mathematical points, dimensionless.

He did not look once again toward the dark house. […] He simply went quietly as if that were his natural manner of moving and passed around the now dimensionless bulk of the house, toward the rear, where the kitchen would be.

1932, William Faulkner, chapter 10, in Light in August, [New York, N.Y.]: Harrison Smith & Robert Haas, →OCLC; republished London: Chatto & Windus, 1933, →OCLC, page 215

A strain is a dimensionless quantity and is usually expressed in percentages. Typical measures for strain are less than 2 mm/m for steel and are often expressed in micro-strain units. One microstrain is the strain producing deformation of one part per million.

2025 September 26, Grant Maloy Smith, “What Is a Strain Gauge Sensor and How Does It Work?”, in DEWESoft, archived from the original on 14 Nov 2025