Liberal democracy has that liberal part though, which means rights and freedom and is pretty clearly in opposition to authoritarianism.

Sure, but there is a strong current trend towards illiberal democracy throughout the world (Brazil, Hungary, Poland, arguably USA).

Authoritarianism does imply reductions in democratic voting.

Democracy and the erosion of human rights are not mutually exclusive, which may be what you meant.

They are more orthogonal than dictatorship and authoritarianism though