noun

1. a space between two things; gap; distance
2. a period of time between two points of time, events, etc.; intervening period
3. the extent of difference between two qualities, conditions, etc.
4. ☆ intervale
5. Math. the set containing all numbers between two given numbers and including one, both, or neither end point
6. Music the difference in pitch between two tones

Etymology: ME enterval, intervalle < OFr < L intervallum, lit., space between two palisades or walls < inter-, between + vallum, palisade, wall