幽す[yuusu] to confine to a room
幽闇[yuuan] gloom
幽雅[yuuga] refinement
幽界[yuukai] hades
幽閑[yuukan] quiet and secluded

幽鬼[yuuki] ghost
幽客[yuukaku] orchid
幽居[yuukyo] hermitage
幽境[yuukyou] solitude
幽契[yuukei] secret promise made to the gods

暗欝[anutsu] gloom
陰欝[inutsu] gloom
欝積[usseki] accumulation (e.g. of emotions, grievances, etc.)
憂欝症[yuuutsushou] melancholia
躁欝病[souutsubyou] manic depression

欝血[ukketsu] blood congestion
欝蒼[ussou] thick
欝憤[uppun] resentment
悒欝[yuuutsu] depression
欝金[ukon] turmeric (Curcuma domestica)