Modifiers matching grump:

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

Simple categories matching principled:

• person,
• campaigner,
• businessman,
• dictator,
• hero,
• miser,
• soldier,
• warrior,
• adventurer,
• policeman,
• technologist,
• scientist,
• sailor,
• tyrant,
• fugitive,
• assassin,
• preacher,
• captain,
• grump,
• explorer,
• detective,
• lawyer,