Verb
preach down (third-person singular simple present preaches down, present participle preaching down, simple past and past participle preached down)
(transitive) To speak vehemently against; to decry.
Antonym: preach up
When I teach writing, I always tell my students you should assume that the audience you're writing for is smarter than you. You can't write if you don't think they're on your side, because then you start to yell at them or preach down to them. Tony Kushner