There needs to be something to take the proton. There needs to be a base . A base is a proton acceptor . Compare this to the definition that an acid is a proton donor. Bases are the opposite of acids.
Bases are basic because they take or accept protons .
Hydroxide ion, for example can accept a proton to form water. Br nsted and Lowry realized that not all bases had to have a hydroxide ion. As long as something can accept a proton it is a base. So anything, hydroxide or not, that can accept a proton is a base under the Br nsted-Lowry definition. The water molecules that accept protons when HCl dissolves in water are acting as bases.