Modifiers matching grump:

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

Simple categories matching grouchy:

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