御休みなさい[oyasuminasai] good night
ひと休み[hitoyasumi] rest
運休[unkyuu] service suspended (e.g. trains)
夏季休暇[kakikyuuka] summer vacation
夏休み[natsuyasumi] summer vacation

閑話休題[kanwakyuudai] Now let's return to the main subject
休め[yasume] (Stand) at ease!
気休め[kiyasume] mere consolation
気休めに[kiyasumeni] for peace of mind
休する[kyuusuru] to come to an end

遠隔講義[enkakukougi] distance learning
休講[kyuukou] lecture cancellation
公開講座[koukaikouza] extension lectures
講演[kouen] lecture
講演会[kouenkai] lecture (esp. special engagement by noted speaker)

講義[kougi] lecture
講座[kouza] academic teaching unit
講師[koushi] lecturer
講習[koushuu] short course
講習会場[koushuukaijou] training center