decrease / reduce / diminish

Kyūjitai form of 双六: sugoroku (a Japanese board game with dice like backgammon)

言語: language / 原語: the original language

弦楽器: string instrument, stringed instrument

語源: etymology

現行犯: flagrante delicto, caught red-handed

方言: dialect, provincialism / 放言: careless remark / 法源: source of law / 法眼: second highest rank of Buddhist monk

保元: Japanese era name extended from 1156 to 1159

原子時計: atomic clock (not to be confused with radio clock)

原子核: atomic nucleus