1) General: A surface regarded as the common boundary of two bodies,
or two parts of a system, whether material or non-material.
2) Astro.: The intersection zone between a hot → H II region
and its → associated molecular cloud.
3) Chemistry: The area where two immiscible phases of a dispersion come into contact.
4) Computers: A mechanical equipment or logical program that communicates
information from one system of computing devices or programs to another.
→ inter- + → face.