LIMACON

[li.ma.con] n [F, lit., snail, fr. OF, dim. of limaz slug, snail, fr. L limax; akin to Russ slimak snail and prob. to OE lim birdlime--more at lime] (1874): a curve that is the locus of a variable point on a line as the line revolves about a fixed point of intersection with a circle while the variable point is always a fixed distance along the line from its second and variable point of intersection with the circle