a length (straight or curved) without breadth or thickness; the trace of a moving point

curved in two directions (like the letter S)

a line traced by a point traveling in a constant direction; a line of zero curvature

turn sharply; change direction abruptly

a symmetrical curve representing the normal distribution

a bend or curve, as in a stream or river

a curve (such as a circle) having no endpoints

a double curve resembling the letter S

the curve theoretically assumed by a perfectly flexible and inextensible cord of uniform density and cross section hanging freely from two fixed points