面おも白しろ半はん分ぶん

na-adjective, noun

for fun; half in jest

Describes doing something partly for amusement, often with a lighthearted or not entirely serious attitude. Commonly used with に as an adverb.

• 彼かれは面おも白しろ半はん分ぶんにそんなことを言いったのだろう。

  He probably said that half in jest.

• 面おも白しろ半はん分ぶんで始はじめた趣しゅ味みが、今いまでは仕し事ごとになっている。

  A hobby I started just for fun has now become my job.