# no free lunch theorem

> English word · Proper noun

## Definitions
1. A theorem that implies that no single machine learning algorithm is universally the best-performing algorithm for all problems.

## Etymology
Derives from the phrase there's no such thing as a free lunch.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/no-free-lunch-theorem