開催[kaisai] holding a meeting
開催式[kaisaishiki] opening ceremony (of an event, show, etc.)
開催中[kaisaichuu] in session
共催[kyousai] joint sponsorship
催し[moyooshi] event

催物[moyoushimono] points of interest
催す[moyoosu] to hold (a meeting)
催淫剤[saiinzai] aphrodisiac
催合う[moyau] to co-operate (in enterprises)
催告[saikoku] notification

其れ共[soretomo] or
と共に[totomoni] together with
ドイツ民主共和国[doitsuminshukyouwakoku] German Democratic Republic (i.e. former East Germany)
ドイツ連邦共和国[doitsurenpoukyouwakoku] Federal Republic of Germany (former West Germany)
ビジネススクール入学共通試験[bijinesusukuurunyuugakukyoutsuushiken] business school entrance test

欧州共同体[oushuukyoudoutai] European Community
共に[tomoni] together
共営[kyouei] joint management
共栄[kyouei] mutual prosperity