<p><strong>Noun:</strong></p><ul><li>the distance between the tip of the thumb and the tip of the little finger when the hand is fully extended.</li><li>a unit of length corresponding to this distance, commonly taken as 9 inches (23 centimeters).</li><li>a distance, amount, piece, etc., of this length or of some small extent: a span of lace.</li><li>Civil Engineering, Architecture: the distance between two supports of a structure.</li><li>the structure so supported.</li><li>the distance or space between two supports of a bridge.</li><li>the full extent, stretch, or reach of anything: a long span of memory.</li><li>Aeronautics: the distance between the wing tips of an airplane.</li><li>a limited space of time, as the term or period of living: Our span on earth is short.</li><li>Mathematics: the smallest subspace of a vector space that contains a given element or set of elements.</li></ul><p><strong>Verb:</strong></p><ul><li>to measure by the hand with the thumb and little finger extended.</li><li>to encircle with the hand or hands, as the waist.</li><li>to extend over or across (a section of land, a river, etc.).</li><li>to provide with something that extends over: to span a river with a bridge.</li><li>to extend or reach over (space or time): a memory that spans 90 years.</li><li>Mathematics: to function (in a subspace of a vector space) as a span.</li><li>Archery: to bend (the bow) in preparation for shooting.</li></ul>