involute

Intricate; complex.

Having the margins rolled inward.

Having whorls that enclose and obscure earlier whorls. Used of a gastropod shell.

To curl inward.

The curve traced by a point as if it were on a taut string being unwound from another curve.

Rolled up; wrapped up.

Involved; confusedly mingled.

That which is involved.

In geometry, the curve traced by any point of a flexible and inextensible string when the latter is unwrapped, under tension, from a given curve; or, in other words, the locus of a point in a right line which rolls, without sliding, over a given curve.