Answer: compound that accepts protons
Step-by-step explanation:
According to Bronsted-Lowry theory, a base is a molecule or ion which accepts the proton while an acid is a substance that donates a proton and produces a conjugate base.
An example of Bronsted-Lowry base is hydroxide ion, OH- as shown in the reaction below
CH3COOH(aq) + OH-(aq) <---> CH3COO-(aq) + H2O(l)
The Ethanoic acid acts as an acid by donating a proton to the hydroxide ion which accepts it and forming water, H2O in the end.
Thus, according to bronsted-Lowry, a base is a compound that accepts protons (H+)