Real Dictionary

size
the act or an instance of excluding or the state of being excluded [...]
the dimensions, proportions, amount, or extent of something [...]
the technique of separating and analysing the components of a mixture of liquids or gases by selective adsorption in, for example, a column of powder (column chromatography) or on a strip of paper (paper chromatography) [...]
variable noun: The size of something is how big or small it is. Something's size is determined by comparing it to other things, counting it, or measuring it.