A double point at which two (or more) osculating curves are tangent. The above plot shows the tacnode of the curve 2x^4 - 3x^2 y + y^2 - 2y^3 + y^4 = 0. The capricornoid and links curve have tacnodes at their origins.

acnode | capricornoid | crunode | double point | links curve | osculating curves | spinode