I. interjection
-- used as a conventional expression of good wishes at parting
the party was over; the time had come to say good-bye
Synonyms: adieu, by, bye-bye, ||cheerio, farewell, so long, ||toodle-oo
Related Word: good day, good evening, good morning, good night
Idioms: be good, be seeing you, fare you well, keep in touch, see you (later)
Contrasted words: hello, how do, howdy, hullo
II. noun
Synonyms: parting , adieu, congé, farewell, leave-taking
III. adjective
Synonyms: parting , departing, farewell, valedictory