foul
foul is a valid 4-letter word worth 7 points in Scrabble and 9 points in Words with Friends.
What does foul mean?
Become or cause to become obstructed.
Become soiled and dirty.
Commit a foul; break the rules.
Hit a foul ball.
Make unclean.
“foul the water”
Make impure.
Spot, stain, or pollute.
Characterized by obscenity.
“foul language”
(of a baseball) not hit between the foul lines.
(of a manuscript) defaced with changes.
“foul (or dirty) copy”
Violating accepted standards or rules.
“used foul means to gain power”
Offensively malodorous.
“a foul odor”
Disgustingly dirty; filled or smeared with offensive matter.
“a foul pond”
Especially of a ship's lines etc.
“with its sails afoul”
“a foul anchor”
Highly offensive; arousing aversion or disgust.
An act that violates the rules of a sport.