ない交ぜにする[naimazenisuru] to blend (e.g. truth and lies)
データ交換[deetakoukan] data exchange
メール交換[meerukoukan] exchange of letters
リーダー交代[riidaakoutai] leadership change
意見交換[ikenkoukan] exchange of ideas

一方交通[ippoukoutsuu] one-way traffic
羽交絞め[hagaijime] pinioning
仮名交じり[kanamajiri] mixed writing (characters and kana)
仮名交じり文[kanamajiribun] mixed writing (characters and kana)
賀詞交換[gashikoukan] New Year greetings (parties)

医界[ikai] medical world
医学界[igakukai] medical world
黄金世界[ougonsekai] utopia
下界[gekai] this world
花柳界[karyuukai] red-light district

界隈[kaiwai] neighborhood
界面[kaimen] interface
各界[kakkai] each field
学界[gakkai] academic or scientific world
官界[kankai] bureaucracy

一坪本社[hitotsubohonsha] small company headquarters located in Tokyo simply for name value
一般社会[ippanshakai] general public
印刷社[insatsusha] printing company
運送会社[unsougaisha] shipping company
映画社[eigasha] movie company

下請会社[shitaukegaisha] subcontractor
下層社会[kasoushakai] the underworld
下流社会[karyuushakai] lower classes
会社[kaisha] company
会社員[kaishain] company employee