Modifiers matching grump:

• heartless,
• wealthy,
• grouchy,
• rich,
• covetous,
• impatient,
• ill-tempered,
• fastidious,
• arrogant,
• penny-pinching,
• condescending,
• misanthropic,
• miserly,
• mean,
• gruff,
• grizzled,
• jealous,
• greedy,
• principled,

Simple categories matching grouchy:

• singer,
• grump,
• poet,
• person,
• composer,
• malcontent,
• musician,