夏衣[natsugoromo] summer clothes
夏羽織[natsubaori] summer haori (coat)
夏越し[natsugoshi] keeping over the summer
夏掛け[natsugake] summer-use futon
夏期学校[kakigakkou] summer school

夏期時間[kakijikan] daylight-saving time
夏期大学[kakidaigaku] university summer school
夏季休暇[kakikyuuka] summer vacation
夏菊[natsugiku] early chrysanthemums

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

シュタイナー学校[shutainaagakkou] Steiner school
ビジネススクール入学共通試験[bijinesusukuurunyuugakukyoutsuushiken] business school entrance test
ロボット工学[robottokougaku] robotics
位相幾何学[isoukikagaku] topology
易学[ekigaku] study of divination

遺伝学[idengaku] genetics
遺伝子工学[idenshikougaku] genetic engineering
医化学[ikagaku] medical chemistry
医科大学[ikadaigaku] medical school
医学[igaku] medical science

安全期[anzenki] safe period
暗黒期[ankokuki] eclipse period
一期[ichigo] one's life time
一期[ikki] one term
一期一会[ichigoichie] once-in-a-lifetime encounter (hence should be cherished as such)

一周期[isshuuki] period (in astronomy)
一定期間[itteikikan] fixed interval
延期[enki] postponement
延期になる[enkininaru] to be postponed
沖積期[chuusekiki] alluvial period