源げん頭とう

noun

river source; headwaters

Refers to the geographical origin of a river or stream.

• その川かわの源げん頭とうは深ふかい山やまの中なかにある。

  The source of that river is deep in the mountains.

noun

cause; root; origin

Metaphorical extension of the river-source meaning; used for the fundamental cause or origin of something.

• 問もん題だいの源げん頭とうを探さぐることが大たい切せつだ。

  It is important to find the root cause of the problem.