1. (

• time_interval ,
• interval

) a definite length of time marked off by two instants ;

2. (

• interval

) a set containing all points (or all real numbers) between two given endpoints ;

3. (

• interval ,
• separation

) the distance between things; "fragile items require separation and cushioning" ;

4. (

• interval ,
• musical_interval

) the difference in pitch between two notes ;