All 7 Uses

frontier
in
Dracula
(Edited)

Being practically on the frontier—for the Borgo Pass leads from it into Bukovina—it has had a very stormy existence, and it certainly shows marks of it.
p. 9.7

frontier = national border
Is it a wonder that we were a conquering race, that we were proud, that when the Magyar, the Lombard, the Avar, the Bulgar, or the Turk poured his thousands on our frontiers, we drove them back?
p. 36.4

frontiers = international borders or wilderness areas at the edge of settled areas
Is it strange that when Arpad and his legions swept through the Hungarian fatherland he found us here when he reached the frontier, that the Honfoglalas was completed there?
p. 36.5

frontier = national border
And when the Hungarian flood swept eastward, the Szekelys were claimed as kindred by the victorious Magyars, and to us for centuries was trusted the guarding of the frontier of Turkeyland.
p. 36.6
Aye, and more than that, endless duty of the frontier guard, for as the Turks say, 'water sleeps, and the enemy is sleepless.'
p. 36.6
He must, indeed, have been that Voivode Dracula who won his name against the Turk, over the great river on the very frontier of Turkeyland.
p. 256.5
In his life, his living life, he go over the Turkey frontier and attack his enemy on his own ground.
p. 341.4 *

Definitions:

(1) (frontier as in: the frontier of Tibet)
an international boundary or a wilderness at the edge of a settled area
(2) (frontier as in: the frontier of brain science)
the most recent understandings and achievements in a changing field
(3) (meaning too rare to warrant focus)
Less commonly, frontier can refer to a type of log cabin.