Definition - What does Decanter mean?
A decanter is a vessel used to allow wine to "breathe." It is utilized to improve the perception of aromas, flavors and textures of a wine. The vessel is often made of glass or crystal, and its dimensions and design should allow a large surface of the wine to have contact with the air in order to be functional.
WineFrog explains Decanter
A decanter is reserved for aged wines that have been cellared for a long period. It can also be used for young wines which would be more palatable if exposed to air.
The purpose of decanting is to allow for a large surface area of the wine to have contact with the air. In some instances, this can benefit a wine and make it more palatable, allowing for more characteristics of the wine to be perceived.
The decanter itself should allow for the wine to be poured from the bottle and simultaneously aerate the liquid. The base of the decanter should be wide and voluminous enough to expose the maximum surface of the wine to air. Some decanters have other accessories such as a screen to filter out pieces of cork and/or tartrates and an aerator device, which allows the wine to pour down the sides of the decanter in order to aerate the wine more efficiently.