One of several layers or levels (4)

I believe the answer is:

tier

(Other definitions for tier that I've seen before include "One of two or more rows" , "Rank, level" , "Person joining" , "Echelon" , "Rank - order" .)

I've seen this clue in the Sydney Morning Herald.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.