• (n.) A point where one branch of a curve crosses another branch. See Double point, under Double, a.
A point where a curve intersects itself so that two branches of the curve have distinct tangent lines.
Cru'node noun [ Prob. from Latin crux a cross + E. node .] (Geom.) A point where one branch of a curve crosses another branch. See Double point , under Double , adjective 
crunode A point where one branch of a curve crosses another branch.