definition of
tier

[1] #1 tier n. [grade, level] a relative position or degree of value in a graded group; "lumber of the highest grade". wn

[2] #2 tier n. any one of two or more competitors who tie one another. wn

[3] #3 tier n. [tier up] a worker who ties something. wn

[4] #4 tier n. something that is used for tying; "the sail is fastened to the yard with tiers". wn

[5] #5 tier n. one of two or more layers one atop another; "tier upon tier of huge casks"; "a three-tier wedding cake". wn