改善[kaizen] betterment
勧善懲悪[kanzenchouaku] rewarding good and punishing evil
勧善懲悪劇[kanzenchouakugeki] morality play
偽善[gizen] hypocrisy
偽善者[gizensha] hypocrite

最善[saizen] the very best
慈善[jizen] charity
慈善家[jizenka] charitable person
慈善会[jizenkai] philanthropic society
慈善市[jizenichi] charity bazaar

ゴミ集積場[gomishuusekijou] village garbage collection point
欝積[usseki] accumulation (e.g. of emotions, grievances, etc.)
沖積[chuuseki] alluvial
沖積期[chuusekiki] alluvial period
沖積世[chuusekisei] alluvial epoch (i.e. the Holocene epoch)

沖積層[chuusekisou] alluvium
沖積土[chuusekido] alluvial soil
下積み[shitazumi] lowest social strata
求積[kyuuseki] mensuration
経路積分[keirosekibun] path integral (physics)