The term 'water down' can be defined as to reduce the strength or effectiveness of something. This can be done in a variety of ways, such as adulterating, debasing, hosing, thinning, weakening, diluting, raining, attenuating, and vitiating. ADULTERATE is a 10 letter word meaning to make impure by adding inferior or tainted substances. DEBASE is a 6 letter word meaning to lower in quality or character. HOSE is a 4 letter word meaning to spray with a HOSE. THIN is a 4 letter word meaning to make or become less dense or concentrated. WEAKEN is a 6 letter word meaning to reduce the strength of. DILUTE is a 6 letter word meaning to make weaker or more watery by adding liquid. RAIN is a 4 letter word meaning to fall from the sky in drops of water. ATTENUATE is a 9 letter word meaning to make THIN or slender. VITIATE is a 7 letter word meaning to impair the quality or value of something.