convolution

Short definition from Wiktionary

Noun

1. 1
   A twist or fold.
2. 2
   Any of the folds on the surface of the brain.
3. 3
   The shape of something rotating; a vortex.
4. 4
   The state or condition of being convoluted.
5. 5
   A mathematical operation on two functions that produces a third that expresses how the shape of one is modified by the other; the integral of the product of the two functions after one is reflected about the y-axis and shifted along the x-axis.
6. 6
   A function which maps a tuple of sequences into a sequence of tuples.
7. 7
   One 360° turn in a spring or similar helix.