any one of two or more competitors who tie one another
"In the heated final round, both runners were declared a tier after crossing the finish line at exactly the same time."
one of two or more layers one atop another
"tier upon tier of huge casks"
"a three-tier wedding cake"
One who ties (knots, etc).
"The bride cut the top tier of her three-tiered wedding cake while guests clapped below."
A layer or rank, especially of seats or a wedding cake.
In plain English: A tier is a level, rank, or group within a larger system that separates people or things based on their quality or importance.
"The cake was decorated with three tiers, each smaller than the last."
Usage: Use tier to describe distinct levels in structures like seating arrangements or multi-layered cakes. Do not confuse this noun with the verb "tie," which refers to fastening things together.
To arrange in layers.
"The chef carefully tiered the fruit salad so that each layer of ingredients was clearly visible."
The word tier is a compound formed from tie and the suffix -er. It originally referred to something tied or bound together before evolving into its modern sense of a horizontal layer or rank within a hierarchy.