# anneal

> English word · Verb · IPA /əˈniːl/

## Definitions
1. To subject to great heat and then (often slow) cooling, and sometimes reheating and further cooling, for the purpose of rendering less brittle; to temper; to toughen.
2. To cool glass slowly, to minimize internal stress.
3. To burn colors onto a glass or other surface.
4. To make a double-stranded nucleic acid by pairing a single strand with a complementary strand.
5. To strengthen or harden.

## Etymology
From Middle English anelen, onelen, from Old English onǣlan (“to burn, ignite, set fire to, consume, heat, enlighten, incite, inflame, inspire, kindle”), from Proto-Germanic *ana (“on”) + Proto-Germanic *ailijaną (“to burn”), from Proto-Indo-European *h₂eydʰ- (“to burn”). The double-N spelling may have arisen by analogy with Latinate verbs like announce, annex, and annul.
The word is related to Old English onāl (“that which is burnt, burning; incense”), Old English āl (“fire, burning”), Icelandic eldur (“fire”), Swedish eld (“fire, flame”), Danish ild (“fire”).

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/anneal