難航: have a hard flight, have a rough passage; run into difficulties, have a rough time

高額: large amount of money / 工学: engineering / 光学: optics / 後学: future reference / 好学: love of learning

抗菌: antibacterial / 公金: public funds / 拘禁: detention, imprisonment / 咬筋: masseter muscle / 行金: bank money

勾配: slope, inclination, gradient / 購買: purchase, buying / 紅梅: a type of Japanese plum / 公売: public sale

甲殻類: crustacean

構成中: (software) being in the process of configuring, currently configuring

公国: principality / 皇国: Empire of Japan / 興国: prosperous country / 広告: advertisement / 抗告: (law) interlocutory appeal

項目: item, point / 綱目: main point and details

黄昏: dusk / 後昆: posterity

後端: posterior end / 降誕: regal birth; nativity / 荒誕: nonsense, wild talk