tier vs competition

tier and competition both are nouns.

Word	Noun	Adjective	Verb	Adverb
tier	Yes	No	No	No
competition	Yes	No	No	No

As nouns, competition is a hypernym of tier; that is, competition is a word with a broader meaning than tier:

Other hypernyms of tier include challenger, competitor, contender, rival.

tier (noun)	competition (noun)
one of two or more layers one atop another	the act of competing as for profit or a prize
any one of two or more competitors who tie one another	an occasion on which a winner is selected from among two or more contestants
a relative position or degree of value in a graded group	the contestant you hope to defeat
something that is used for tying	a business relation in which two parties compete to gain customers
a worker who ties something