Definitions from Wiktionary ( )

▸ adjective:  Sure in one's mind, positive; absolutely confident in the truth of something.
▸ adjective:  Not to be doubted or denied; established as a fact.
▸ adjective:  Sure to happen, inevitable; assured.
▸ adjective:  Unfailing; infallible.
▸ adjective:  Fixed; regular; determinate.
▸ adjective:  Particular and definite, but unspecified or unnamed; used to introduce someone or something without going into further detail.
▸ adjective:  (euphemistic, preceded by "a") Used to denote that the speaker is referring to a specific person or thing that they do not want to name directly, implying that the listener should infer the identity of the referent.
▸ adjective:  (preceded by "a", of a person) Named but not previously mentioned.
▸ adjective:  (preceded by "a", of a person) Used before the name of someone famous that people are expected to know.
▸ adjective:  (obsolete) Determined; resolved.
▸ noun:  A surname.

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