From Longman Dictionary of Contemporary Englishpreachpreach /priːtʃ/ ●○○ verb 1 [intransitive, transitive]RRTALK TO somebody to talk about a religious subject in a public place, especially in a church during a servicepreach to Christ began preaching to large crowds.preach on/about The vicar preached a sermon about the prodigal son. He traveled the southern states, preaching the gospel.2 [transitive]PERSUADE to talk about how good or important something is and try to persuade other people about this Alexander has been preaching patience.preach the virtues/merits/benefits of something a politician preaching the virtues of a free market3 [intransitive]ADVISE to give someone advice, especially about their behaviour, in a way that they think is boring or annoyingpreach about grown-ups preaching about the evils of drugs4 → preach to the converted/choir → practise what you preach at practise(5)→ See Verb table
Examples from the Corpus
preach• After completing his studies, in which he excelled in philosophy and theology, he was ordained and was assigned to preaching.• His jailers realized that his ransom would exceed those of the other prisoners, so Raymond was continuously tortured for preaching.• Campaigns that have merely preached abstinence have always failed.• He also preached at Blackfriars on Sundays and a mid-week lecture in Milk Street.• You're always preaching honesty, and then you lie to me.• Mom, stop preaching - I'm old enough to take care of myself.• In those days there was little opportunity to hear Gospel preaching in Shropshire.• How couldst thou preach of heaven and hell in such a careless, sleepy manner?• Renaissance humanism preached respect for the greatness of the human being as an individual: it stressed personal intelligence and ability.• Gordon was preaching the morality of scholarship.preaching the gospel• It was only a few minutes into Sunday when Vice President Gore started preaching the gospel.• He would tour the world quietly preaching the gospel of surfing.preach the virtues/merits/benefits of something• He may preach the virtues of an empty bank account, but Damon is fairly obsessed with filling his own.• By preaching the merits of downsizing, they have provided bosses with arguments for measures that tough economic times have required anyway.Origin preach (1200-1300) Old French prechier, from Late Latin praedicare, from Latin dicare “to say publicly” 