Tier1. (n.) One who, or that which, ties.
2. (n.) A child's apron covering the upper part of the body, and tied with tape or cord; a pinafore.
3. (n.) A row or rank, especially one of two or more rows placed one above, or higher than, another; as, a tier of seats in a theater.
Thesaurus Entries
Indian file, array, articulation, band, bank, bed, bedding, belt, buzz, category, catena, catenation, chain, chain reaction, chaining, concatenation, connection, consecution, continuum, couche, course, cycle, deck, descent, drone, echelon, endless belt, endless round, file, filiation, floor, gallery, gamut, gradation, grade, group, grouping, hum, layer, league, ledge, level, line, lineage, measures, monotone, nexus, order, overlayer, overstory, pendulum, periodicity, pigeonhole, plenum, powder train, progression, queue, range, rank, recurrence, reticulation, rotation, round, routine, row, run, scale, seam, sequence, series, shelf, single file, spectrum, stage, step, story, stratum, string, substratum, succession, superstratum, swath, thickness, thread, topsoil, train, underlayer, understory, understratum, windrow, zone