When it comes to finding alternative ways to describe someone who is increasingly irritable or displeased, there are several synonyms for the word "grumpier" that can capture the essence of this mood. One option could be "crankier", which implies a heightened level of frustration or agitation. Another synonym, "sulkier", suggests a touch of gloominess or resentment in one's demeanor. For a more intense description, "cantankerous" might be fitting, as it signifies a persistent and irascible attitude. Additionally, "ornery" conveys a sense of stubbornness and irritability. Exploring these synonyms enhances one's language diversity and ability to articulate different shades of grumpiness.