to damage severely or harm (something), esp. with reference to its excellence, value, usefulness, etc.

The water stain spoiled the painting. Drought spoiled the corn crop.

to diminish or impair the quality of; affect detrimentally

Bad weather spoiled their vacation.

to impair, damage, or harm the character or nature of (someone) by unwise treatment, excessive indulgence, etc.

to spoil a child by pampering him.

Archaic . to strip (persons, places, etc.) of goods, valuables, etc.; plunder; pillage; despoil.

Archaic . to take or seize by force.

to become bad, or unfit for use, as food or other perishable substances; become tainted or putrid

Milk spoils if not refrigerated.

to plunder, pillage, or rob.

Often, spoils. booty, loot, or plunder taken in war or robbery.

the act of plundering.

an object of plundering.

Usually, spoils.

the emoluments and advantages of public office viewed as won by a victorious political party

the spoils of office.

prizes won or treasures accumulated

a child's spoils brought home from a party.

waste material, as that which is cast up in mining, excavating, quarrying, etc.

an imperfectly made object, damaged during the manufacturing process. ?

be spoiling for

Informal . to be very eager for; be desirous of

It was obvious that he was spoiling for a fight.