An example of something for which one might have an appetite is money.
An appetite for learning.
An example of someone who has a hearty appetite is a person who eats a big lunch.
An appetite for knowledge.
America's appetite for fossil fuels.
Origin of appetite
- Middle English apetit from Old French from Latin appetītus strong desire from past participle of appetere to strive after ad- ad- petere to seek pet- in Indo-European roots
From American Heritage Dictionary of the English Language, 5th Edition