開発【かいはつ】
development, exploitation (of resources)
開放【かいほう】
opening (a door, window, etc.), leaving open, opening up (e.g. to the public), allowing (public) access
開始【かいし】
start, commencement, beginning, initiation
公開【こうかい】
opening to the public, making available to the public, exhibiting, unveiling, release (of a film, information, etc.), disclosure, publication
展開【てんかい】
development, evolution, progression, unfolding, (plot) twist, expansion, spreading out, extending, deployment, building up, expansion (of an algebraic expression), development (of a three-dimensional shape), extraction (of compressed data), decompression, unpacking
開催【かいさい】
holding (a conference, exhibition, etc.), opening, hosting (e.g. the Olympics)
開幕【かいまく】
raising the curtain, opening (of an event), start, beginning
再開【さいかい】
reopening, resumption, restarting
開会【かいかい】
opening of a meeting
開票【かいひょう】
counting ballots, tally (of votes)
開設【かいせつ】
establishment, opening, setting up, inauguration
打開【だかい】
break in the deadlock
非公開【ひこうかい】
private, non-public, secret, closed-door, closed
開拓【かいたく】
reclamation (e.g. of wasteland), cultivation, development, pioneering, opening up (e.g. of a new market), breaking new ground, trailblazing
開店【かいてん】
opening a new shop, opening a shop (for the day)
開通【かいつう】
opening (of a new road, railway, etc.), going into operation (e.g. telephone communication), beginning services, reopening (e.g. of a road to traffic), resumption of services
疎開【そかい】
dispersal, evacuation, removal, spreading out (troops), deployment
開閉【かいへい】
opening and shutting, opening and closing
開廷【かいてい】
court session, trial
開拓者【かいたくしゃ】
pioneer, settler, colonist