1) Area between 2) Area between buildings 3) Future challenge for NASA 1) Interiority 2) Interval 
The region between adjacent veins.
• (n.) Intervening space.
Any space between two similar objects, such as a costal interspace or interval between two ribs. ... (05 Mar 2000) ... 
(in´tәr-spās) a space between similar structures.
In'ter·space` noun [ Latin interspatium . See Inter- , and Space .] Intervening space. Bp. Hacket. 
Type: Term Pronunciation: in′tĕr-spās Definitions: 1. Any space between two similar objects, such as a costal interspace or interval between two ribs.