The resilience of liberal democracies against illiberal, authoritarian, and populist surges hinges on a citizenry that accurately understands the concept of liberal democracy. However, research shows that many citizens understand democracy in ambiguous ways, such that they simultaneously hold liberal and authoritarian associations with democracy. This ambiguity raises two important questions: First, to what extent do citizens understand what are the essential ingredients of liberal democracy, without which it cannot be defined as such? Second, what are the factors shaping how well citizens understand liberal democracy? Based on an analysis of 12 European democracies, we find that citizens are generally able to recognise electoral and liberal features as essential for democracy, but struggle to differentiate liberal democracy from its nondemocratic alternatives. Further, we show that citizens with a well-informed understanding of liberal democracy have rather homogeneous profiles across Europe, with age, education, and political interest having the strongest effect on citizens’ level of democratic understanding. These findings contribute to the literature on democratic backsliding, and suggest that when democratically elected politicians engage in illiberal or antidemocratic practices to promote their own interests, a majority of the European electorate does not recognise these practices as a threat to liberal democracy.