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)

陰鬱[inutsu] gloom
鬱積[usseki] accumulation (e.g. of emotions, grievances, etc.)
抗鬱[kouutsu] antidepressant
鬱を散じる[utsuwosanjiru] to chase one's gloom away
鬱陶しい[uttoushii] gloomy (e.g. mood)

鬱病[utsubyou] melancholia
躁鬱[souutsu] manic-depressive (bipolar)
躁鬱病[souutsubyou] manic depression
鬱血[ukketsu] blood congestion
鬱蒼[ussou] thick