noun (chemistry) a surface forming a common boundary between two things (two objects or liquids or chemical phases).
noun (computer science) a program that controls a display for the user (usually on a computer monitor) and that allows the user to interact with the system.
— synonyms: user_interface
noun the overlap where two theories or phenomena affect each other or have links with each other.
noun (computer science) computer circuit consisting of the hardware and associated circuitry that links one device with another (especially a computer and a hard disk drive or other peripherals).
— synonyms: port
Examples
“Public relations firms often serve as the interface between a company and the press.”
“If water and oil are mixed together, they tend to separate, and at equilibrium they are in different strata with an oil-water interface in between.”
“The data is sent over the air interface to the remote system.”