to deliver a sermon in the course of a religious service
to explain or proclaim (a religious idea or system) in public
(often + at) to give advice, instructions, or warnings in an officious, tiresome, or highly moral manner
to speak about, explain, or proclaim (a religious idea or system) in public
to preach the gospel
to deliver (a sermon) publicly
to advocate (something) earnestly
preacher noun
[Middle English prechen via Old French prechier from Latin praedicare to proclaim publicly, from prae- + dicare to proclaim]