parting vs valediction

parting and valediction both are nouns.

Word	Noun	Adjective	Verb	Adverb
parting	Yes	No	No	No
valediction	Yes	No	No	No

As nouns, valediction is a hyponym of parting; that is, valediction is a word with a more specific, narrower meaning than parting:

parting (noun)	valediction (noun)
the act of departing politely	the act of saying farewell
a line of scalp that can be seen when sections of hair are combed in opposite directions	a farewell oration (especially one delivered during graduation exercises by an outstanding member of a graduating class)