bye vs concession

bye and concession both are nouns.

Word	Noun	Adjective	Verb	Adverb
bye	Yes	No	No	No
concession	Yes	No	No	No

As nouns, concession is a hypernym of bye; that is, concession is a word with a broader meaning than bye:

bye: an automatic advance to the next round in a tournament without playing an opponent
concession: the act of conceding or yielding

Other hypernyms of bye include conceding, yielding.

bye (noun)	concession (noun)
a farewell remark	a contract granting the right to operate a subsidiary business
an automatic advance to the next round in a tournament without playing an opponent	a point conceded or yielded
	the act of conceding or yielding