1. A device, especially the gas pedal of a motor vehicle, for increasing speed.
2. Chemistry A substance that increases the speed of a reaction.
3. Physics A particle accelerator.
4. Business An organization that provides new businesses with mentoring, funding, and other services and resources, usually for a limited period of a few months, in exchange for equity.
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.