from
The Collaborative International Dictionary of English v.0.48
Tier \Tier\, n. [Perhaps fr. OF. tire, F. tire; probably of
Teutonic origin; cf. OHG. ziar[imac] ornament, G. zier, AS.
t[imac]r glory, ti['e]r row, rank. But cf. also F. tirer to
draw, pull; of Teutonic origin. Cf. {Attire}, v. t., {Tire} a
headdress, but also {Tirade}.]
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.
[1913 Webster]
{Tiers of a cable}, the ranges of fakes, or windings, of a
cable, laid one within another when coiled.
[1913 Webster]