A fundamental, generic term used when referring to the measurement (count, amount) of a scalar, vector, number of items or to some other way of denominating the value of a collection or group of items.
User Defined Definitions
"how much there is or how many there are of something that you can quantify"
"an adequate or large amount"
"the concept that something has a magnitude and can be represented in mathematical expressions by a constant or a variable"