お大事に[odaijini] take care of yourself
暗黒大陸[ankokutairiku] Dark Continent (i.e. Africa)
伊勢大神宮[isedaijinguu] the Grand Shrines of Ise
伊勢大廟[isetaibyou] the Grand Shrines of Ise
偉大[idai] greatness

医科大学[ikadaigaku] medical school
医大[idai] medical university
井の中の蛙大海を知らず[inonakanokawazutaikaiwoshirazu] parochial
一大[ichidai] one large ...
一大事[ichidaiji] serious affair

藻掻く[mogaku] to struggle
海藻[kaisou] seaweed
褐藻[kassou] brown algae
珪藻[keisou] diatom
珪藻土[keisoudo] diatomaceous soil

紅藻[kousou] red algae
才藻[saisou] poetic talent
稚海藻[wakame] wakame (species of edible brown seaweed, Undaria pinnatifida)
藻草[mogusa] water-plants