obscure

To render obscure; to darken; to make dim; to keep in the dark; to hide; to make less visible, intelligible, legible, glorious, beautiful, or illustrious.

To hide, put out of sight etc.

To conceal oneself; to hide.

Dark, faint or indistinct.

Hidden, out of sight or inconspicuous.

Difficult to understand.

“an obscure passage or inscription;    The speaker made obscure references to little-known literary works.”

Not well-known.

Unknown or uncertain; unclear.

“The etymological roots of the word "blizzard" are obscure and open to debate.”