These days, moxie is a synonym for energy and pep, courage and determination, know-how and expertise.
The original moxie was a patent medicine and tonic Moxie Nerve Food invented by Dr. Augustin Thompson and sold in New England in the 1870s. According to one story, Dr. Thompson got the name from a Lieutenant Moxie who discovered the South American plant that was the elixir's secret ingredient. Another story traces moxie to an Algonquin word.
Within a decade, Thompson had carbonated Moxie and was marketing it as a beverage with a "delicious blend of the bitter and the sweet." The soft drink and its advertising slogans (among them Make Mine Moxie!) caught on around the country.
By 1930, moxie had acquired its earliest modern sense of "energy, pep." Appropriately enough, although the drink's popularity has fizzled in most of the U.S., the word moxie determinedly lives on.