Known but not specifically named; indeterminate; indefinite; one or some; sometimes used independently as a noun, and meaning certain persons; see also "one".
Unfailing; infallible.
Fixed or stated; regular; determinate.
Not to be doubted or denied; established as a fact.
Sure, positive, not doubting.
Actually existing; sure to happen; inevitable.
Having been determined but not specified.
Unnamed or undescribed members (of).
Not known; unidentified; not well known.
A variable (usually x, y or z) whose value is to be found.
A person of no identity; a nonentity
Any thing, place, or situation about which nothing is known; an unknown fact or piece of information.