Usage Note: The adverb thusly was created in the 1800s as an alternative for thus in sentences such as Hold it thus or He put it thus. It appears to have been first used by humorists, who may have been imitating the speech of poorly educated people straining to sound stylish. The word has subsequently gained some currency in educated usage, but it has long been deplored by usage commentators as a "nonword." A large majority of the Usage Panel found it unacceptable in 1966, and this sentiment was echoed nearly forty years later in our 2002 survey, in which 86 percent of the Panel disapproved of the sentence His letter to the editor ended thusly: "It is time to stop fooling ourselves."
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 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.