사이가 · 사이를 · 사이에 (between)
space between, gap; relationship
Example
은행은 우체국과 병원 사이에 있어요.
The bank is between the post office and the hospital.
Word parts
Also means relationship: 사이가 좋다 = to get along well.
Good to know
Pattern: A와/하고 B 사이에 = between A and B. Often shortened to 새 in speech.