夷俗[izoku] customs of the barbarians
雅俗[gazoku] refined and vulgar
還俗[genzoku] return to secular life
旧俗[kyuuzoku] old customs
古俗[kozoku] old custom

州俗[shuuzoku] local customs
淳風美俗[junpuubizoku] good morals and manners
世俗[sezoku] common customs
世俗化[sezokuka] secularization
世俗主義[sezokushugi] secularism