Dears hev and wwh,

The math term* is indeed intercept (as a noun), which is the place where one line crosses another. Don't confuse that with the verb intersect which is what the lines are doing at the intercept!

* once again I have only ever heard this one term to describe this concept but God knows there must be some bizarre math book out there which has decided to call intercepts, say, lemmings. Or something equally ludicrous.