1 The amount of chroma in a colour as a proportion of all the colour, both chromatic (1) and achromatic (1), the admixture of grey causing the colour to appear desaturated. It is one of the three major dimensions of colour, the other two being hue and lightness. The Munsell chroma scale of saturation ranges from grey (zero) to the most saturated level (14). See also chromaticity, Munsell colour system.
2 In log-linear analysis, the state of a model that contains all main effects and interactions and in which observed and expected frequencies are therefore equal.
3 More generally, the state or quality of being soaked or imbued with something to the fullest extent possible. [From Latin saturare, -atum to soak, from satur full or sated, from satis enough + -ation indicating a process or condition]