# span

Pronunciation: say "SPAN" US/UK /spæn/, AUS /spæːn/

## Verb

1. To extend through or continue across a particular period of time.
   - Simple: To last through or cover a period of time.
   - _The dynasty spanned four centuries before it finally collapsed._
   - _Their friendship would span five decades and two continents._
2. To extend across or reach over the distance between two points or sides.
   - Simple: To reach from one side of something to the other.
   - _The new suspension bridge spans the entire bay._
   - _Her hand can span a full octave on the keyboard._
10. To measure something by the width of the outstretched hand with the fingers extended, or with the fingers wrapped around the object.
   - Simple: To measure something with your open hand, from your thumb to your little finger.
   - _The old farmer would span a beam with his outstretched hand to judge its width._
   - _He spanned the horse's girth with both hands, his fingers meeting at the top._
12. To generate an entire vector space by means of linear combinations of a given set of vectors.
   - Simple: In math, to fill an entire space using sums and multiples of a set of vectors.
   - _The standard basis vectors span all of three-dimensional space._
   - _The chosen wavelet functions span the space of signals the model needs to represent._
16. To fetter or hobble an animal, especially a horse, by binding its legs to keep it from wandering.
   - Simple: To tie an animal's legs together so it cannot walk far away.
   - _The drovers would span the horses each evening before making camp._
   - _She spanned the pony with a soft rope so it could graze without straying._

## Noun

3. The distance covered by an arch, beam, girder, truss, roof, or bridge between its supports or abutments.
   - Simple: The distance that a bridge, beam, or arch reaches between its supports.
   - _The main span of the suspension bridge stretches nearly a mile._
   - _Builders added a central column because the roof's span was too great for unsupported timber._
4. A brief stretch of time or a small extent of space.
   - Simple: A short length of time or a small amount of space.
   - _The company doubled its profits within a span of six months._
   - _A short span of beach lay between the rocks and the pier._
5. The distance between the wingtips of an aircraft or a bird.
   - Simple: The distance from the tip of one wing to the tip of the other on a bird or plane.
   - _The albatross has the greatest span of any living bird, sometimes exceeding eleven feet._
   - _Engineers reduced the fighter's span so it could fit on the carrier's elevator._
6. A portion of something extending along its length; a continuous section or subsequence.
   - Simple: A part of something measured along its length.
   - _Crews replaced a damaged span of track north of the station._
   - _The editor cut a long span of dialogue from the second act._
7. An informal measure of length equal to the width of an outstretched hand, from the tip of the thumb to the tip of the little finger.
   - Simple: The distance across an open hand, from the thumb tip to the little finger tip, used to measure things.
   - _Lacking a tape measure, the carpenter sized up the board in spans._
   - _The gap between the stones was barely a span wide._
8. The stretch of a cable, wire, rope, or chain that runs from one support to the next.
   - Simple: The length of a wire, rope, or chain between two of its supports.
   - _Ice built up along one span of the transmission line until it snapped._
   - _The cable car's final span stretches more than a kilometer between towers._
9. Any of various traditional units of length based on the handspan, especially the English unit of nine inches, one eighth of a fathom and equal to 22.86 centimeters.
   - Simple: An old unit of length based on the width of a hand, equal to about nine inches.
   - _A medieval survey recorded the wall as forty spans high._
   - _Under the old English system, a span equaled half a cubit._
11. The set of all linear combinations of the vectors in a given set.
   - Simple: In math, everything you can make from a set of vectors by adding them and multiplying them by numbers.
   - _The span of the two basis vectors is the entire plane._
   - _Because the third vector lies in the span of the first two, it adds nothing new._
13. A rope made fast at both ends so that a purchase can be hooked to the bight, or made fast at the center so that both ends can be used.
   - Simple: On a ship, a rope fixed at both ends so a hook or pulley can hang from its middle.
   - _The mate rigged a span across the hatch and hooked the cargo tackle into its bight._
   - _With the span made fast at its center, both free ends were used to steady the boom._
14. A pair of horses or other animals driven together, especially horses alike in color, form, and action. *(Canada, US)*
   - Simple: Two horses or other animals that work together pulling as a pair, often matching in color and size.
   - _The carriage rolled up behind a handsome span of matched bays._
   - _He traded two cows for a span of oxen to break the new field._
15. The time required to execute a parallel algorithm on an unlimited number of processors, set by the longest chain of steps that must run one after another.
   - Simple: In computing, the least possible time a task needs, even with endless computers working on it together.
   - _Adding more processors cannot push the running time below the algorithm's span._
   - _Engineers reduced the span of the computation so it scaled better across the cluster._

## Verb

17. Of horses or other driven animals, to be matched in color, form, and action. *(dated, US)*
   - Simple: Of two horses, to look and move alike, like a matching pair.
   - _These bays span perfectly; you could not tell one from the other at a trot._
   - _The judge said the sorrels spanned better than any pair at the fair._
18. Past tense of spin. *(dated)* — simple past of spin
   - Simple: Past tense of spin. An old form: most people now say spun.
   - _The weather vane span wildly as the storm blew in._
   - _By lamplight she span the flax into fine, even thread._

## Origin

**Meanings 3–9, 11, 13–15** — From Middle English spanne, from Old English spann, from Proto-Germanic *spannō ("span, handbreadth"), tracing back to a Proto-Indo-European root *(s)pend- ("to stretch"). It is related to Dutch span and German Spanne. The sense "pair of horses" probably comes instead from Old English ġespan, ġespann ("a joining, fastening, clasp, yoke").
**Meanings 1–2, 10, 12, 16–17** — From Middle English spannen, from Old English spannan, from Proto-Germanic *spannaną ("to stretch, span"). It is related to German spannen and Dutch spannen.
**Meaning 18** — From Middle English span, from Old English spann, the first and third person singular past tense of Proto-Germanic *spinnaną ("to spin").

Source: DictionaryAI, https://dictionaryai.com/define/span (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).