Expressing dissatisfaction is a way to communicate one's displeasure with a situation or person. MOAN and COMPLAIN are two words that can be used to express dissatisfaction. MOAN is a low, prolonged sound expressing physical or mental suffering, while COMPLAIN is to express dissatisfaction, pain, uneasiness, censure, resentment, or grief. Both words can be used to express dissatisfaction in a variety of situations.