spline

UK: /splaɪn/ US: (splīn)

Inflections of 'spline' (v): (⇒ conjugate)

splines

v 3rd person singular

splining

v pres p

splined

v past

splined

v past p

WordReference Random House Unabridged Dictionary of American English © 2025

spline  (splīn), n., v., splined, splin•ing. 
n. 

1. a long, narrow, thin strip of wood, metal, etc.;
   slat.
2. a long, flexible strip of wood or the like, used in drawing curves.
3. [Mach.]
   • Mechanical Engineering any of a series of uniformly spaced ridges on a shaft, parallel to its axis and fitting inside corresponding grooves in the hub of a gear, etc., to transmit torque.
   • Mechanical Engineering See feather key. 
4. Building a thin strip of material inserted into the edges of two boards, acoustic tiles, etc., to make a butt joint between them;
   a feather.
5. Mathematics a function that has specified values at a finite number of points and consists of segments of polynomial functions joined smoothly at these points, enabling it to be used for approximation and interpolation of functions.

v.t. Mach. 

6. Mechanical Engineering to provide with a spline or key.
7. Mechanical Engineering to provide with a keyway.

• 1750–60; origin, originally East Anglian dialect, dialectal; perh. akin to splint; compare Old English splin spindle

Collins Concise English Dictionary © HarperCollins Publishers::

spline / splaɪn/ noun

1. any one of a series of narrow keys (external splines) formed longitudinally around the circumference of a shaft that fit into corresponding grooves (internal splines) in a mating part: used to prevent movement between two parts, esp in transmitting torque
2. a long narrow strip of wood, metal, etc; slat
3. a thin narrow strip made of wood, metal, or plastic fitted into a groove in the edge of a board, tile, etc, to connect it to another

verb

1. (transitive) to provide (a shaft, part, etc) with splines

Etymology: 18th Century: East Anglian dialect; perhaps related to Old English splin spindle; see splint