Emily Dickinson Lexicon

SPAN, n.¹ [Sax. span; D. span; G. spanne; Dan. spand; a span in measure; Sw. span, a span in measure, and a set of coach horses, G. gespann; verbs, Sax. spannan, to span, to unite; gespanian, to join; D. and G. spannen; Dan. spander, to strain, stretch, bend, yoke. This word is formed on the root of bend, L. pando. The primary sense is to strain, stretch, extend, hence to join a team, Dan. forspand, D. gespan.]

1. The space from the end of the thumb to the end of the little finger when extended; nine inches; the eighth of a fathom. – Holder.
2. A short space of time. Life's but a span; I'll every inch enjoy. – Farquhar.
3. A span of horses, consists of two of nearly the same color, and otherwise nearly alike, which are usually harnessed side by side. The word signifies properly the same as yoke, when applied to horned cattle, from buckling or fastening together. But in America, span always implies a resemblance in color at least; it being an object of ambition with gentlemen and with teamsters to unite two horses abreast that are alike.
4. In seamen's language, a small line or cord, the middle of which is attached to a stay.