講演【こうえん】
lecture, address, speech
講師【こうし】
speaker, lecturer, lecturer (at a university or college), instructor, part-time teacher, tutor (at a cram school)
講座【こうざ】
course (e.g. of lectures), academic university unit (professor, lecturers, etc.)
講義【こうぎ】
lecture
講堂【こうどう】
auditorium, lecture hall
講和【こうわ】
reconciliation (between warring nations), (making of) peace
聴講【ちょうこう】
lecture attendance, auditing
休講【きゅうこう】
cancellation (of a lecture, class, etc.)