ローム層[roomusou] stratum of loam
亜成層圏[aseisouken] substratosphere
一層[issou] much more
沖積層[chuusekisou] alluvium
下層[kasou] lower strata (classes)

下層階級[kasoukaikyuu] proletariat
下層社会[kasoushakai] the underworld
下層土[kasoudo] subsoil
化石層[kasekisou] fossil bed
階層[kaisou] class

犬薄荷[inuhakka] catnip (Nepeta cataria)
意志薄弱[ishihakujaku] weak-willed
佳人薄命[kajinhakumei] beauties die young
極薄[kyokuhaku] ultrathinness
軽薄[keihaku] frivolous

軽佻浮薄[keichoufuhaku] frivolous and thoughtless
厚薄[kouhaku] thickness
精神薄弱[seishinhakujaku] mental retardation
精薄[seihaku] mental retardation (pejorative)
浅薄[senpaku] shallowness