PREY UPON

{v.} 1. To habitually kill and eat; catch for food. * /Cats prey on mice./ 2. To capture or take in spoils of war or robbery. * /Pirates preyed on American ships in the years just after the Revolutionary War./ 3. To cheat; rob. * /Gangsters preyed on businesses of many kinds while the sale of liquor was prohibited./ 4. To have a tiring and weakening effect on; weaken. * /Ill health had preyed on him for years./ * /Business worries preyed on his mind./