penumbra

他的职业处于灰色地带，既不算全职也不算自由职业。

His career exists in a ___penumbra between full-time employment and freelancing.

在日食期间，我们可以看到太阳被月球的半影部分遮挡。

During the solar eclipse, we could see the sun partially obscured by the moon's ___penumbra.