Farewell
Part of speech: adjective
Definition: parting; valedictory; final;
Part of speech: interjection
Definition: goodbye
Part of speech: verb
Definition: To bid farewell or say goodbye
Part of speech: noun
Definition: A wish of happiness or welfare at parting, especially a permanent departure; the parting compliment; a goodbye; adieu. An act of departure; leave-taking; a last look at, or reference to something.
Goodbye
Part of speech: noun
Definition: An utterance of goodbye, the wishing of farewell to someone.
Part of speech: interjection
Definition: farewell; a formula used to another person or persons when the speaker or writer or the person addressed to is departing.
Example sentence: Like the old soldier of the ballad, I now close my military career and just fade away, an old soldier who tried to do his duty as God gave him the light to see that duty. Goodbye.