"tier" in the noun sense
1. grade, level, tier
a relative position or degree of value in a graded group
"lumber of the highest grade"
any one of two or more competitors who tie one another
3. tier, tier up
a worker who ties something
something that is used for tying
"the sail is fastened to the yard with tiers"
one of two or more layers one atop another
"tier upon tier of huge casks"
"a three-tier wedding cake"
Source: WordNet® (An amazing lexical database of English)
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