In predicative use: Unaccompanied or unsupported by others; alone, solitary. Unsupported by other evidence. Obsolete. rare.

Of fortune, affairs, etc.: Variable, mutable. †Of a person: Having a doubtful or uncertain title.

without (†one's) book (in early use also †bout book): without the aid of a book, from memory, by rote; (figurative) without authority.

(un-, prefix1 affix 1.)

Not authoritative; having no authority.