convolution (n.)

1540s, "state of being rolled upon itself; a turning, winding, fold, or gyration," noun of state from Latin convolutus, past participle of convolvere "to roll together," from assimilated form of com "with, together" (see con-) + volvere "to roll" (from PIE root *wel- (3) "to turn, revolve"). Meaning "act of rolling or winding together" is from 1590s. Related: Convolutions.