a. Proper or sound condition.
b. Mental or emotional state; spirits: was in fine fettle.
2. Metallurgy Loose sand or ore used to line the hearth of a reverberatory furnace in preparation for pouring molten metal.
tr.v. fet·tled, fet·tling, fet·tles
To line the hearth of (a reverberatory furnace) with loose sand or ore in preparation for pouring molten metal.
[From Middle English fetlen, to make ready, possibly from Old English fetel, girdle.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.