approximation theory

noun

: a branch of mathematics that is concerned with finding or deriving the simplest function that matches a limited set of data

The fading of interest in orthogonal polynomials is rightly reflected in a lack of courses being taught, says Chihara (Purdue U.-Calumet), and they are now taught in passing, if at all, in courses on approximation theory or mathematical physics.

—Reference & Research Book News, 1 Aug. 2011

Word History

First Known Use

1924, in the meaning defined above

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!