As a Noun: 1. A talk that someone gives in order to teach people about a particular subject. English = lecture. 2. A person who talks to a group of people about a particular subject. English = speaker. 3. A person who teaches at a university or college. English = lecturer. 4. A formal talk that someone gives to lots of people; a formal talk given by a religious figure. English = speech; sermon. 5. A formal statement that someone makes, especially in a court of law. English = testimony. As a Verb or Adjective: 1. To give a talk in order to teach people about a particular subject. English = lecture. 2. To give a formal talk to lots of people. English = make a speech. 3. (When referring to a religious figure) to give a formal talk in a place of worship. English = preach, give a sermon. 4. To make a formal statement, especially in a court of law. English = testify.