tier vs worker

tier and worker both are nouns.

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

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

tier (noun)	worker (noun)
one of two or more layers one atop another	sterile member of a colony of social insects that forages for food and cares for the larvae
any one of two or more competitors who tie one another	a person who works at a specific occupation
a relative position or degree of value in a graded group	a member of the working class (not necessarily employed)
something that is used for tying	a person who acts and gets things done
a worker who ties something