言葉遊び【ことばあそび】 word game; wordplay; playing with words
無効【むこう】 invalid; void; ineffective; unavailable
会費【かいひ】 membership fee
初年度【しょねんど】 first year; initial (year)
かえって《却って》 on the contrary; rather; all the more; instead
再生【さいせい】 resuscitation; regeneration; restoration to life / reformation; rehabilitation / playback; regeneration (sound, etc.); view (of a video clip) / reclamation; recovery / rebirth; reincarnation
亜鉛【あえん】 zinc (Zn)
開催【かいさい】 holding (a conference, exhibition, etc.); opening; hosting (e.g. the Olympics)
安全性【あんぜんせい】 safety; security
ただし《但し》 but; however; provided that
抑える【おさえる】 to keep within limits (e.g. spending); to restrain (e.g. emotions); to control; to curb; to hold in check / to hold back (e.g. an enemy); to check; to curb; to contain; to quell; to subdue; to suppress; to repress