Hidden, out of sight or inconspicuous.
Dark, faint or indistinct.
Difficult to understand.
Not well-known.
Unknown or uncertain; unclear.
To hide, put out of sight etc.
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.
Certain in one's knowledge or belief.
Physically secure and certain, non-failing, reliable.
Certain to act or be a specified way.
Yes, expressing noncommittal agreement or consent.
Yes; of course.
You're welcome; polite response to being thanked.
Without doubt, certainly.