An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

1) Aeronautics: The distance between the wing tips of an airplane.
2) Math.: The smallest subspace of a → vector space that contains a given element or set of elements.

M.E. spanne, sponne, spayn; O.E. span(n), spon(n) "distance between the thumb and little finger of an extended hand;" cf. Ger. Spanne, Du. span.

Bâzé "extension of both arms when streched out," related to bâzu "arm" (Mid.Pers. bâzûk "arm;" Av. bāzu- "arm;" cf. Skt. bāhu- "arm, forearm;" Gk. pechys "forearm, arm, ell;" O.H.G. buog "shoulder;" Ger. Bug "shoulder;" Du. boeg; O.E. bôg, bôh "shoulder, bough;" E. bough " a branch of a tree;" PIE *bhaghu- "arm"); from Av. vībāzu- "fathom, measure of the outstretched arms."