Chrominance (chroma or C for short) is the signal used in video systems to convey the color information of the picture, separately from the accompanying luma signal (or Y for short). Chrominance is usually represented as two color-difference components: U = B′ − Y′ (blue − luma) and V = R′ − Y′ (red − luma). Each of these differenc...
(from the article `television`) Chrominance, defined as that part of the colour specification remaining when the luminance is removed, is a combination of the two independent ...
The color component of a video signal that includes information about hue (shade) and saturation (intensity).
Colour component of a video signal, details ...
A colour term defining the hue and saturation of a colour. Does not refer to brightness
(C) The color portion of a video signal.
A colour term defining the hue and saturation of a colour. Does not refer to brightness. 
The colour information of a colour video signal.
The level of saturation of a color
the difference in color quality between a color and a reference color that has an equal brightness and a specified chromaticity.
Shortened to Chroma or C. The signal in component video systems that contains the colour information for the picture. The monochrome part of the picture is luma or luminance.