kickoff vs place kick

kickoff and place kick both are nouns.

Word	Noun	Adjective	Verb	Adverb
kickoff	Yes	No	No	No
place kick	Yes	No	No	No

As nouns, place kick is a hypernym of kickoff; that is, place kick is a word with a broader meaning than kickoff:

kickoff: (football) a kick from the center of the field to start a football game or to resume it after a score
place kick: (sports) a kick in which the ball is placed on the ground before kicking

Other hypernyms of kickoff include place-kicking, beginning, commencement, start.

kickoff (noun)	place kick (noun)
(football) a kick from the center of the field to start a football game or to resume it after a score	(sports) a kick in which the ball is placed on the ground before kicking
a start given to contestants
the time at which something is supposed to begin