tier
noun
[ tɪə ]
• each in a series of rows or levels of a structure placed one above the other.
• "a tier of seats"
Similar:
row,
rank,
bank,
line,
layer,
level,
plane,
floor,
storey,
deck,
Origin:
late 15th century: from French tire ‘sequence, order’, from tirer ‘elongate, draw’.