Noun
y-intercept (plural y-intercepts)
(mathematics) A point at which a line crosses the y-axis of a Cartesian grid.
In this particular equation, the constant m determines the slope or gradient of that line, and the constant term b determines the point at which the line crosses the y-axis, otherwise known as the y-intercept. Source: Internet
This form of a line's equation is called the slope-intercept form, because c can be interpreted as the y-intercept of the line, that is, the y-coordinate where the line intersects the y-axis. Source: Internet