preach /priːtʃ/ BrE AmE verb
[ Date: 1200-1300 ; Language: Old French ; Origin: prechier , from Late Latin praedicare , from Latin dicare 'to say publicly' ]
1 . [intransitive and transitive] to talk about a religious subject in a public place, especially in a church during a service
preach 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] 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 market
3 . [intransitive] to give someone advice, especially about their behaviour, in a way that they think is boring or annoying
preach about
grown-ups preaching about the evils of drugs
4 . preach to the converted/choir to talk about what you think is right or important to people who already have the same opinions as you
⇨ practise what you preach at ↑ practise (5)