personal grudge

Kyūjitai form of 私鉄 (“private railway”)

原書: original document, original work / 原初: source, first, original / 厳暑: extreme heat

源流: source of something, especially a river

病原体: pathogen, causal agent of a disease

病原: cause or source of a disease, pathogenesis, etiology

原発: Short for 原子力発電所. nuclear power plant / 原発: Short for 原子力発電. nuclear power generation / 原発: (medicine) primary (e.g. primary tumor)

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