Worse to better

adulterate
(v)
ǝ-DULL-tǝr-ate
Meaning

make impure by adding inferior or tainted substances; water down

1st Sample Sentence

Many petrol vendors adulterate the petrol with water.

Root

adulterare (falsify, corrupt, commit adultery) (Latin)

Mnemonics

when a child becomes adult he loses his purity and innocence. so any thing adulterated is contaminated or has lost its purity. Adults are more impure than children, so adulterate means to make impure dull+the+rate = impure, means to decrease the rate