[in.ter.val] n [ME intervalle, fr. MF, fr. L intervallum space between ramparts, interval, fr. inter- + vallum rampart--more at wall] (14c) 1 a: a space of time between events or states b Brit: intermission
2. a: a space between objects, units, points, or states b: difference in pitch between tones
3: a set of real numbers between two numbers either including or excluding one or both of them
4: one of a series of fast-paced runs interspersed with jogging for training (as of a runner) -- in.ter.val.lic adj