bourn, frontier, marge, verge.
bourne, landmark,

The _boundary_ was originally the _landmark_, that which marked off one
piece of territory from another. The _bound_ is the _limit_, marked or
unmarked. Now, however, the difference between the two words has come to
be simply one of usage. As regards territory, we speak of the
_boundaries_ of a nation or of an estate; the _bounds_ of a college, a
ball-ground, etc. _Bounds_ may be used for all within the _limits_,
_boundary_ for the limiting line only. _Boundary_ looks to that which is
without; _bound_ only to that which is within. Hence we speak of the
_bounds_, not the _boundaries_, of a subject, of the universe, etc.; we
say the students were forbidden to go beyond the _bounds_. A _barrier_
is something that bars ingress or egress. A _barrier_ may be a
_boundary_, as was the Great Wall of China. _Bourn_, or _bourne_, is a
poetical expression for _bound_ or _boundary_. A _border_ is a strip of
land along the _boundary_. _Edge_ is a sharp terminal line, as where
river or ocean meets the land. _Limit_ is now used almost wholly in the
figurative sense; as, the _limit_ of discussion, of time, of
jurisdiction. _Line_ is a military term; as, within the _lines_, or
through the _lines_, of an army. Compare BARRIER; END.

Antonyms:

center, citadel, estate, inside, interior, land, region, territory.

Prepositions:

The boundaries _of_ an estate; the boundary _between_ neighboring
territories.

* * * * *

BRAVE.

Synonyms:

adventurous, courageous, fearless, undaunted,
bold, daring, gallant, undismayed,
chivalric, dauntless, heroic, valiant,
chivalrous, doughty, intrepid, venturesome.

The _adventurous_ man goes in quest of danger; the _bold_ man stands out
and faces danger or censure; the _brave_ man combines confidence with
resolution in presence of danger; the _chivalrous_ man puts himself in
peril for others' protection. The _daring_ step out to defy danger; the
_dauntless_ will not flinch before anything that may come to them; the
_doughty_ will give and take limitless hard knocks. The _adventurous_
find something romantic in dangerous enterprises; the _venturesome_ may
be simply heedless, reckless, or ignorant. All great explorers have been
_adventurous_; children, fools, and criminals are _venturesome_. The
_fearless_ and _intrepid_ possess unshaken nerves in any pla