円墳[enpun] round burial mound
古墳[kofun] ancient (mound) tomb
前方後円墳[zenpoukouenfun] keyhole-shaped tumulus (form of ancient Imperial grave)
墳墓[funbo] grave
墳丘[funkyuu] tumulus

古墳時代[kofunjidai] Tumulus period (of Japanese history)
方墳[houfun] flat-topped burial mound
墳丘墓[funkyuubo] tomb embedded in a Yayoi period barrow
上円下方墳[jouenkahoufun] burial mound with square flat base and round top