an intervening period of time

an interval of 50 years.

a period of temporary cessation; pause

intervals between the volleys of gunfire.

a space between things, points, limits, etc.; interspace

an interval of ten feet between posts.

Mathematics .

the totality of points on a line between two designated points or endpoints that may or may not be included.

any generalization of this to higher dimensions, as a rectangle with sides parallel to the coordinate axes.

the space between soldiers or units in military formation.

Music . the difference in pitch between two tones, as between two tones sounded simultaneously (harmonic interval) or between two tones sounded successively (melodic interval).

Chiefly New England . intervale.

Cards . a period in a game for placing bets.

British . an intermission, as between the acts of a play. ?

at intervals

at particular periods of time; now and then

At intervals, there were formal receptions at the governor's mansion.

at particular places, with gaps in between

detour signs at intervals along the highway.

noun

continuation

noun

breach , breathing space * , comma , delay , distance , downtime , five * , gap , hiatus , interim , interlude , intermission , interregnum , interruption , lacuna , layoff , letup , lull , meantime , opening , parenthesis , pausation , period , playtime , rest , season , space , spell , ten * , term , time , time-out , wait , whilenotes:an interval is a gap in time or space , whereas an interlude (literally \'between games\') generally functions to fill such a gap , thus occupy an interval , interspace , interstice , separation , armistice , break , caesura , intermezzo , interstice (space between) , meantim , pause , phase , recess , respite , rupture , span