tier

noun

• each in a series of rows or levels of a structure placed one above the other:a tier of seats [in combination]:the room was full of three-tier metal bunks
• each of a number of successively overlapping ruffles or flounces on a garment: a full skirt gathered into three tiers
• a level or grade within the hierarchy of an organization or system:companies have taken out a tier of management to save money