spline vs treenail

spline

noun
  • Long thin piece of metal or wood. 

  • 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. 

  • 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. 

  • 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. 

  • Any of a number of smooth curves used to join points. 

  • A strip of wood or other material inserted into grooves in each of two pieces of wood to provide additional surface for gluing. 

verb
  • To smooth (a curve or surface) by means of a spline. 

  • To fit with a spline. 

  • To fasten to or together with a spline. 

treenail

noun
  • A wooden peg or pin used as a fastener. 

How often have the words spline and treenail occurred in a corpus of books? (source: Google Ngram Viewer )