spline

Etymology

Mid-1700s East Anglian dialect. Origin uncertain but perhaps from Old Danish splind or North Frisian splinj and ultimately related to the root of splinter.

noun

1. Long thin piece of metal or wood.
2. (woodworking) A strip of wood or other material inserted into grooves in each of two pieces of wood to provide additional surface for gluing.
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. (mathematics, computing) Any of a number of smooth curves used to join points.
5. 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.
6. (mechanics) Ridges or teeth on a drive shaft that mesh with grooves in a mating piece and transfer torque to it, maintaining the angular correspondence between them.

verb

1. (mathematics, computing) To smooth (a curve or surface) by means of a spline.
2. (engineering) To fit with a spline.
   Machining a straight spline with a lathe. Sometimes the task of splining a shaft comes up during a repair. Instead of sending out the job, use this setup to mill the splines on a lathe. 1965 August, Popular Science, volume 187, number 2, page 133
3. (engineering) To fasten to or together with a spline.
   Engineers did not think two crankshafts could be synchronized. Wood, by splining the shafts in each gear box, proved it could be done. 1935 September, Popular Mechanics, volume 64, number 3, page 408
   These packs can be holding or driving devices, depending on what they are splined to. 2004, Jack Erjavec, TechOne automatic transmissions, page 311
   Splined bars are a big recent trend. Originally used in racing, the idea is to have a straight torsion bar with the ends splined like an axle and separate arms that fit on each end to mount the end links 2011, Mark Savitske, How to Make Your Muscle Car Handle, page 85