a variable whose values are one or more categories. • some categorical variables may have a numerical label but do not have any numerical significance statistically, e.g. it makes no sense to calculat [..]

A variable whose value ranges over categories, such as {red, green, blue}, {male, female}, {Arizona, California, Montana, New York}, {short, tall}, {Asian, African-American, Caucasian, Hispanic, Nativ [..]

A categorical variable may be nominal or ordinal.  Categorical variables can be defined based on attributes without any associated order (e.g., medical admission, elective surgery or emergency surgery); these are called nominal variables.  A categorical variable can also be defined based on attributes that are ordered (e.g., height such as high, me [..]

n. a variable with a number of possible values, yet these are fixed and limited into set groups or classes. Examples includes blood group or blood type (A, B, AB, and O) or political affiliation (Repu [..]

A variable that is defined by membership and not rank or by scores of measurement.

is a characteristic with defined categories, such as gender (categories: male and female) or blood group (categories: A, B, AB, 0). Categorical data have to be recorded in exhaustive and exclusive categories that is, there must be enough categories so that each observation fits into a category (exhaustive), and one category only (exclusive).