| 開け広げる | to open wide, to reveal hidden contents |
| 間を開ける | to leave space (between) |
| 開けっ放す | to leave open |
| 穴開き銭 | perforated coin |
| 穴が開く | to have a hole, to be pierced (with a hole) |
| 穴を開ける | to make a hole (in) |
糸口を開く 緒を開く | to find a clue, to make a beginning |
御開き お開き | breakup (of a ceremony, wedding, party, meeting, etc.), closure |
| 開業を許す | to be licensed to practice (e.g. law), to be allowed to open a business |
| 開銀 | development bank |
| 開悟 | wisdom, enlightenment |
| 開傘 | opening of a parachute |
| 開析台地 | dissected plateau |
| 開腹術 | laparotomy |
| 距離を開く | to open the distance |
| 公開の席 | in public |
| 道を開く | to open up doors, to pave the way |
| 戦端を開く | to open hostilities, to take up arms (against) |
| 戸を開ける | to open the door |
| 開き鯵 | split and dried saurel |
| 店を開く | to open a business |
| 道を切り開く | to open a path |
| 開梱 | open (as of a pack) |
| 宇宙開発計画 | space development project (program, programme) |
| 開放感 | sense of liberation, feeling of freedom |
| 開校記念日 | anniversary of the founding of the school |
| 開催国 | host country (e.g. for a conference) |
| 開催地 | place where a meeting (conference, etc.) is held, venue |
| 開催日 | date(s) (e.g. for exhibition) |
| 開拓者精神 | pioneering spirit |
| 開拓地 | reclaimed land, cleared land, area opened for development |
| 開通式 | formal opening (e.g. of a rail-road) |
| 開発計画 | development project (program, programme, plan) |
| 開票結果 | results of the vote count |
| 開票速報 | quick (flash) report of votes counted |
| 開票率 | percentage of votes counted so far |
| 開幕戦 | opening game, (season) opener |
| 公開練習 | public workout |
| 公開録音 | public recording |
| 未開人 | barbarian, savage, savage (primitive) people (race) |
| 未開地 | savage (barbaric) land, backward region, undeveloped area |
| 急展開 | rapid development |
| 口開け | beginning, opening, commencement (e.g. of sales), first sale |
| 開管 | open pipe |
| 開管分析 | open tube test |
| 開坑 | opening of mine |
| 開所 | open a new business |
| 開度 | divergence, aperture |
| 開発輸入 | develop-and-import formula |
| 開放血管系 | open blood-vascular system |
| 開放性結核 | open tuberculosis |
| 開放創 | open wound |
開法 開方 | extraction of roots, evolution |
| 株式公開買付制度 | tender offer, take-over bid, TOB |
| 水平展開 | grassroots (organization, development, movement) |
| ヨーロッパ復興開発銀行 | European Bank for Reconstruction and Development, EBRD |