お使[otsukai] errand
み使い[mitsukai] angel
悪天使[akutenshi] evil angels
かな使い[kanazukai] kana orthography
雁の使い[karinotsukai] (a) letter

旧仮名使い[kyuukanazukai] former (i.e. before the post-WWII reforms) kana usage in writing the readings of kanji
金を使う[kanewotsukau] to spend money
駆使[kushi] free use
軍使[gunshi] truce bearer
権利行使[kenrikoushi] exercise of a right

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