The sovereign can entrust the government to the entire people or to the majority of them. This is given the name 'democracy'.
Gist of Idea
If the sovereign entrusts government to at least half the citizens, that is 'democracy'
Jean-Jacques Rousseau (The Social Contract (tr Cress) , III.03)
Note that democracy is here a form for the executive, not for the legislature. I take it that the general will must come close to unanimity, and a mere 51% support for fundamental legislation would never do. Increase the percentage with the importance?
Rousseau,Jean-Jacques: 'The Basic Political Writings', ed/tr. Cress,Donald A. [Hackett 1987], p.178