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

大晦日[oomisoka] New Year's Eve
韜晦[toukai] hidden (talents, etc.)
晦渋[kaijuu] ambiguous
晦冥[kaimei] darkness
大晦[ootsugomori] the last day of the year

晦ます[kuramasu] to abscond
晦む[kuramu] to be dazzled by
自己韜晦[jikotoukai] concealing one's talents, position, status, intentions, etc.
天地晦冥[tenchikaimei] The world is covered in darkness