Definition
A grumbler is someone who complains in a low, indistinct, and often continuous manner. It's like a persistent undercurrent of dissatisfaction that never quite stops. Think of it as someone who is never fully content and always finds fault, even in good situations. They are often less direct than a whiner but more constant in their negativity. Unlike someone who openly argues, a grumbler mutters their discontent under their breath. They create a pervasive atmosphere of negativity around them.