Attenuate

Attenuate-v
1-(vti) to reduce the size, strength, or density of something, or to become thinner, weaker, or less dense
2-(vt) to reduce the virulence of a bacterium or virus, for example, by exposing it to heat or producing a culture of it in a special medium

Synonyms
satisfy
assuage
calm
sooth
ease
intensify (antonym)