Chapter Vanishing to Variable of V by Webster's Dictionary (1913 Edition)

3. (Naut.) (a) A shifting wind, or one that varies in force. (b) pl. Those parts of the sea where a steady wind is not expected, especially the parts between the trade-wind belts.

Independent variable (Math.), that one of two or more variables, connected with each other in any way whatever, to which changes are supposed to be given at will. Thus, in the equation x² - y² = R², if arbitrary changes are supposed to be given to x, then x is the independent variable, and y is called a function of x. There may be two or more independent variables in an equation or problem. Cf. Dependent variable, under Dependent.