Harmonic-interval

noun
1.
See under (def 6).
[in-ter-vuh l] /ˈɪn tər vəl/
noun
1.
an intervening period of time:
an interval of 50 years.
2.
a period of temporary cessation; pause:
intervals between the volleys of gunfire.
3.
a space between things, points, limits, etc.; interspace:
an interval of ten feet between posts.
4.
Mathematics.

5.
the space between soldiers or units in military formation.
6.
Music. the difference in pitch between two tones, as between two tones sounded simultaneously (harmonic interval) or between two tones sounded successively (melodic interval)
7.
Chiefly New England. .
8.
Cards. a period in a game for placing bets.
9.
British. an intermission, as between the acts of a play.
Idioms
10.
at intervals,

/ˈɪntəvəl/
noun
1.
the period of time marked off by or between two events, instants, etc
2.
the distance between two points, objects, etc
3.
a pause or interlude, as between periods of intense activity
4.
(Brit) a short period between parts of a play, concert, film, etc; intermission
5.
(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.
the ratio of the frequencies of two sounds
7.
(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 not
8.
at intervals

n.

early 14c., from Old French intervalle (14c.), earlier entreval (13c.), from Late Latin intervallum “space, interval, distance,” originally “space between palisades or ramparts,” from inter “between” (see inter-) + vallum “rampart” (see wall). Metaphoric sense of “gap in time” was present in Latin.

interval in·ter·val (ĭn’tər-vəl)
n.