Using words in your historical fiction that weren’t used during the book’s time period detracts from the book. You might have a good plot and writing style, but your readers are expecting a well-researched narrative.
One of my favorite tasks when editing historical fiction is checking the etymology of words. Picking out the time-traveling words takes instinct and curiosity. I once researched “cute” out of editorial instinct and learned that it is short for “acute” and was originally synonymous with intelligent rather than adorable. Considering the time period of the novel I was editing, “cute” didn’t make the cut.
My two favorite online resources for checking etymology are: http://www.etymonline.com/ and https://www.merriam-webster.com/. These links are good starting points, but many words and phrases require more research.
Do you have a question you would like me to answer? Let me know in the comments.