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

断トツ[dantotsu] the best
一刀両断[ittouryoudan] cutting in two with a single stroke
引っ張り剪断強度[hipparisendankyoudo] peel strength (conductor from substrate)
英断[eidan] resolution
横断[oudan] crossing

横断歩道[oudanhodou] pedestrian crossing
果断[kadan] decisive
間断[kandan] break in time
強制中断[kyouseichuudan] forcing to a stop
禁断[kindan] prohibition

峡谷[kyoukoku] glen
溪谷[keikoku] valley
千仭の谷[senjinnotani] bottomless ravine
谷あい[taniai] valley
谷川[tanigawa] mountain stream

谷底[tanisoko] bottom of valley or ravine
幽谷[yuukoku] deep ravine
蟀谷[komekami] temple (of the forehead)
谷まる[kiwamaru] to terminate