1. A space between things; a void space intervening between any two objects; as, an interval between two houses or hills.
'Twixt host and host but narrow space was left,
A dreadful interval. --Milton.
2. Space of time between any two points or events; as, the interval between the death of Charles I. of England, and the accession of Charles II.
3. A brief space of time between the recurrence of similar conditions or states; as, the interval between paroxysms of pain; intervals of sanity or delirium.
4. Mus. Difference in pitch between any two tones.
At intervals, coming or happening with intervals between; now and then. “And Miriam watch'd and dozed at intervals.” --Tennyson.
Augmented interval Mus., an interval increased by half a step or half a tone.