preach

Concise Oxford English Dictionary © 2008 Oxford University Press:
preach/priːtʃ/

▶verb

• 1 deliver a religious address to an assembled group of people.

  ■ publicly proclaim (a religious message).

• 2 earnestly advocate (a principle): my parents always preached tolerance.

  ■ (preach at) give moral advice to (someone) in a self-righteous way.

– derivatives
preacher noun,
preachiness noun,
preachy adjective.

– origin ME: from OFr. prechier, from L. praedicare ‘proclaim’, in eccles. L. ‘preach’.