non-dimensional
/ˌnɒndʌɪˈmɛnʃ(ə)n(ə)l/ /ˌnɒndʌɪˈmɛnʃən(ə)l/ /ˌnɒndɪˈmɛnʃ(ə)n(ə)l/adjective
1Lacking dimension; having no extent in any spatial dimension.
2 Science. Of a physical quantity: having a numerical value independent of the choice of units of measurement; = dimensionless. Also (of an equation): composed of dimensionless terms.
Origin
Late 19th century; earliest use found in Edwin Abbott (1838–1926), headmaster and writer. From non- + dimensional.