to utter slanderous or abusive statements against (somebody or something), or defame them
It has now been fashionable, for near half a century, to defame and vilify the house of Stuart, and to exalt and magnify the reign of Elizabeth — Dr Johnson
vilification /-fiʹkaysh(ə)n/ noun
vilifier noun
[Middle English vilifien to make less valuable, from late Latin vilificare, from Latin vilis of little worth + facere to make, do]