The killing of a person without malice aforethought but with either the intention to commit an unlawful act that leads to an unintended death, or with an otherwise murderous intent that is extenuated by some partial defense, such as acting under the influence of an extreme emotional disturbance occasioned by a substantial provocation on the part of the victim.
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.