The etymology is unclear, and is presumed to come from a regional word: bistro, bistrot, bistingo, or bistraud, a word in the Poitou dialect which means a "lesser servant." Another offered is bistouille or bistrouille, a colloquial term from the northern area of France, which is a mixture of brandy and coffee; precisely the kind of beverage that could be served at a bistro. The first recorded use of the word appears in 1884,, and again in 1892 ("bistrot").
A popular folk etymology of the word claims that it originated among Russian troops who occupied Paris following the Napoleonic Wars. In taverns they would shout the Russian быстро (bystro, “quickly”) to the waiters, so that "bistro" took on the meaning of a place where food was served quickly. This etymology is rejected, due to the 69 year gap between the proposed origin and the first attestation. In Russia restaurants are not traditionally called bistros, and the concept of the fast-serving restaurant as used in Russian is seen as a French import, unrelated to the supposed Russian origin.