in·ter·val (?n?t?r-v?l)n.1. A space between objects, points, or units, especially when making uniform amounts of separation: We set up hurdles at intervals of 15 yards around the track.2. An amount of time between events, especially of uniform duration separating events in a series: We ran laps at 30-second intervals.3. A segment of an athletic workout in which an athlete runs, swims, or does other exercise over a series of predetermined distances at regular time increments with intermittent rests.4. Mathematics a. A set of numbers consisting of all the numbers between a pair of given numbers along with either, both, or none of the endpoints.b. A closed interval.c. An open interval.d. A half-open interval.e. A line segment representing the set of numbers in an interval.5. Chiefly British An intermission, as between acts of a play.6. Music The difference, usually expressed in the number of steps, between two pitches.Idiom: at intervals In a series separated by space or time: trees planted at intervals; coughing at intervals.[Middle English intervalle, from Old French, from Latin intervallum : inter-, inter- + vallum, rampart.]in?ter·val?ic, in?ter·val?lic (-v?l??k) adj.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.interval (??nt?v?l) n1. the period of time marked off by or between two events, instants, etc2. the distance between two points, objects, etc3. a pause or interlude, as between periods of intense activity4. Brit a short period between parts of a play, concert, film, etc; intermission5. (Classical Music) music the difference of pitch between two notes, either sounded simultaneously (harmonic interval) or in succession as in a musical part (melodic interval). An interval is calculated by counting the (inclusive) number of notes of the diatonic scale between the two notes: the interval between C and G is a fifth. 6. (General Physics) the ratio of the frequencies of two sounds7. (Mathematics) maths the set containing all real numbers or points between two given numbers or points, called the endpoints. A closed interval includes the endpoints, but an open interval does not8. at intervals a. occasionally or intermittentlyb. with spaces between[C13: from Latin intervallum, literally: space between two palisades, from inter- + vallum palisade, rampart] intervallic adjCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014in?ter?val (??n t?r v?l) n. 1. an intervening period of time: an interval of 50 years. 2. a period of temporary cessation; pause. 3. a space between things, points, limits, etc.: an interval of ten. 4. Math. a. the totality of points on a line between two designated points or endpoints that may or may not be included. b. any generalization of this to higher dimensions, as a rectangle with sides parallel to the coordinate axes. 5. the space between soldiers or units in military formation. 6. the difference in pitch between two tones sounded simultaneously or successively. 7. Brit. intermission (def. 1). Idioms: at intervals, a. now and then. b. here and there. [1250?1300; Middle English