Foul

The card player was accused of a foul when he was caught cheating during the poker game.

The foul rag that he used to clean the car only made it dirtier.

The car's engine started running foul, causing it to sputter and stall.

The old sailor taught the young boy how to make a foul.

The foul smoke from the burning forest obscured the sun and created a gloomy atmosphere.