Vocabulary What does 祭壇 (さいだん, saidan) mean? 祭壇 (さいだん, saidan) means altar. Quick factsReadingさいだんRomajisaidanPart of speechnoun 祭壇さいだんsaidanaltar1noun altarKanji in this word祭festival; a religious rite壇altar, platform, dais; raised mound