The word "grouch" is often used to describe someone who is irritable, grumpy or bad-tempered. If you are looking for synonyms for this common term, some good options include curmudgeon, crab, sourpuss, and complainer. Other potential synonyms might include moaner, whiner, sour-faced, crank, or grump. Each of these words is accurate in its own way, and can help you to better describe someone who is in a bad mood or feels grumpy and dissatisfied. Keep these words in mind the next time you encounter someone who fits this description, or when you want to add a little flavor to your writing.