All 4 Uses

frontier
in
Jasmine, by Bharati Mukherjee
(Auto-generated)

That's what excited Prakash about electronics. It was a frontier, especially in India, and no one was staying back to service the goods that were flooding in.
p. 88.4 *

frontier = wilderness (figuratively; a place of opportunity)
I'm out in my Rabbit worried that Bud's gotten home and not found me or Du, worried that the frontier of madness is closer than I guessed.
p. 218.7

frontier = border
Every night the frontier creeps a little closer.†
p. 20.1
Adventure, risk, transformation: the frontier is pushing indoors through uncaulked windows.†
p. 240.9

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.