The point at which a curve or function crosses the y-axis (i.e., when 
in two dimensions).
y-Intercept
See also
Line, x-InterceptExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "y-Intercept." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/y-Intercept.html