n. pl. knives (nīvz)
1. A cutting instrument consisting of a sharp blade attached to a handle.
2. A cutting edge; a blade.
v. knifed, knif·ing, knifes
1. To use a knife on, especially to stab; wound with a knife.
2. Informal To betray or attempt to defeat by underhand means.
To cut or slash a way through something with or as if with a knife: The boat knifed through the waves.
under the knife Informal
[Middle English knif, from Old English cnīf, from Old Norse knīfr.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. 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.