Convolution \Con`vo*lu"tion\, n.

1. The act of rolling anything upon itself, or one thing upon another; a winding motion.

O'er the calm sea, in convolution swift, The feathered eddy floats. --Thomson.

2. The state of being rolled upon itself, or rolled or doubled together; a tortuous or sinuous winding or fold, as of something rolled or folded upon itself. --Blackmore.

3. (Anat.) An irregular, tortuous folding of an organ or part; as, the convolutions of the intestines; the cerebral convolutions. See Brain.

Source: Webster's Revised Unabridged Dictionary (1913)