上級副社長[joukyuufukushachou] senior vice president
正副[seifuku] original and copy
副う[sou] to meet (one's expectations, etc.)
副因[fukuin] secondary cause
副会長[fukukaichou] vice president (of a club or organization, organisation)

副議長[fukugichou] vice-chairman
副業[fukugyou] side job
副見出し[fukumidashi] subhead
副作用[fukusayou] reaction

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