spline

Short definition from Wiktionary

Noun

1. 1
   A long, thin piece of metal or wood.
2. 2
   A strip of wood or other material inserted into grooves in each of two pieces of wood to provide additional surface for gluing.
3. 3
   A flexible strip of metal or other material, that may be bent into a curve and used in a similar manner to a ruler to draw smooth curves between points.
4. 4
   Any of a number of smooth curves used to join points.
5. 5
   A ridge or tooth on a drive shaft that meshes with a corresponding groove in a mating piece and transfers torque to it, maintaining the angular correspondence between the pieces; either the ridge or the groove, as part of a set of both (splines); the whole set of ridges and grooves.
6. 6
   A rectangular piece that fits grooves like key seats in a hub and a shaft, so that while the one may slide endwise on the other, both must revolve together.

Verb

1. 1
   To smooth (a curve or surface) by means of a spline.
2. 2
   To fit with a spline.
3. 3
   To fasten to or together with a spline.