[n] one of two or more layers one atop another; "tier upon tier of huge casks"; "a three-tier wedding cake"
[n] something that is used for tying; "the sail is fastened to the yard with tiers"
[n] a worker who ties something
[n] any one of two or more competitors who tie one another
[n] a relative position or degree of value in a graded group; "lumber of the highest grade"