飛竜: a wyvern / 飛龍: a "flying dragon" (shogi piece)

篳篥: a cylindrical double reed wind instrument used in the gagaku music of Japan

百日の説法屁一つ: “a hundred days of sermonizing, one fart” → a metaphor for how extreme effort something that one has put great effort into can come to nothing after even a slight mistake, much as a hundred days of serious spiritual study can be lost to the winds

火の鳥: A phoenix, more specifically as in Western mythology.

記念碑: monument

比重: specific gravity; relative importance

標準語: the standard language (of a country); standard Japanese

百科全書: encyclopedia

皇妃: an empress / 口碑: a legend / 工費: construction costs / 公比: a common ratio; a geometric ratio / 公妃: a duchess / 公費: public expenditure / 叩扉: beating on a door; a visit to someone

叩扉: to beat on a door; to visit someone / 光被: to spread widely (said of a light, or of magnanimous favor of someone in power)