Tier list fandom. row, rank, or layer, one atop the other: Their seats are on the third tier. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more. one of…. ] Tier definition: One of a series of rows placed one above another. How to use tier in a sentence. TIER helps industrial facilities find innovative ways to reduce emissions and invest in clean technology to stay competitive and save money. A tier list is a ranking system that allows you to rank anything in tiers from the best to worst. The meaning of TIER is a row, rank, or layer of articles; especially : one of two or more rows, levels, or ranks arranged one above another. TIER meaning: 1. one of a number of galleries, as in a theater.