To make better; improve.
To make a formal alteration (in legislation, a report, etc.) by adding, deleting, or rephrasing.
To become better.
An act of righting a wrong; compensation.
To alter; to vary; to make or become different.
The measured magnitude of a variable.
random variable
A variable, often the set of x values plotted on a graph.
A measurable quantity capable of taking on a number of values.