balun

(plural baluns)
- An electronic device for connecting a balanced transmission line to an unbalanced one.
From balanced and unbalanced
balun - Computer Definition

A passive device, often a transformer, used to couple an electrically balanced device, medium, or system and an electrically unbalanced device, medium, or system. A balun commonly is used to connect an electrically balanced twisted pair to an electrically unbalanced coaxial cable. The term balun is a contraction of balanced to unbalanced transformer. See also balanced, coaxial cable, passive, transformer, twisted pair, and unbalanced.

(BALanced UNbalanced) A device that connects a balanced line to an unbalanced line; for example, a twisted pair to a coaxial cable. A balanced line is one in which both wires are electrically equal. In an unbalanced line, such as a coax, one line has different properties than the other.