Dimness, Obscurity, Unclear, Indistinct
noun, な adjective
明瞭 is "clarity." If there is not any of this clarity, then you have dimness or obscurity.
ふめいりょう
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
説明書を読んだんですが、あまりに不明瞭だったので、新モデルの実力についてちょっと不安に思っています。
I’m a little worried about this new model’s capabilities because even though I read the instructions, they were really unclear.