definitive

adj

1. explicitly defined
2. determining finally, conclusive, decisive

   “definitive vote”

   “She will have the definitive say in the matter, after consulting her board of directors.”

3. definite, authoritative and complete

   “A strict and definitive truth.”

   “Some definitive […] scheme of reconciliation.”

4. limiting; determining

   “a definitive word”

5. general, not issued for commemorative purposes
6. (obsolete)Determined; resolved.

   “Never crave him. We are definitive.”

noun

1. a word, such as a definite article or demonstrative pronoun, that defines or limits something
2. an ordinary postage stamp that is part of a series of all denominations or is reprinted as needed to meet demand