What is a general name for things that are being measured?
Kilometere is a distance measurement unit.
Kilogram is a weight measurement unit.
The Gini index is measuring inequality.
distance, weight and inequality are all ... ?
Solution 1:
Source:OED
Quantity, n.
I. An amount, a portion.
a. A specified or definite amount of an article or commodity; a (large, small, etc.) portion or measure; also without of-adjunct. Also (occas.): an amount of something immaterial.