jackboot

1. A sturdy, laceless, leather boot reaching up to or above the knee, popular during the 17th and 18th centuries but recently worn by soldiers in the Nazi regime.
2. Oppressive, bullying, or authoritarian tactics.
3. A person or organization that employs such tactics.

The association of this word with Nazis is very strong; in fact, an anti-war organization awarding a "Golden Jackboot" jokes that "The Golden Jackboot^TM Award is a Goering-Goebells (sic) Production, a subsidiary of Reichstag Enterprises (otherwise known as the DC Anti-War network)." Since one dictionary gives "Hessian boot" as a synonym, these boots indeed may have traditionally been popular in Germany (though the same dictionary also cites "Wellington boot" as another synonym, and that certainly doesn't sound German). There seems to have been a German rock band calling themselves "Jackboot" but I can find almost no information about them; allmusic.com says only that they were active in the 1980s.

I myself have mostly heard the word as part of the phrase "jackbooted thugs," as applied to overzealous or downright brutal police or military members, or enforcers of totalitarian governments who might kick down the doors of people's dwellings to make arrests. George Orwell's essay "Politics and the English Language" (1946) cites "jackboot" (along with "mailed fist") as a characteristic word of writing aimed at glorifying war, and later as a "worn-out and useless phrase." However, it seems in nearly sixty years that the use of the word has continued in use by anyone who wants to make it clear that they disapprove of some behavior for its unjustified force.