barrier

As nouns the difference between challenge and barrier

is that challenge is a confrontation; a dare while barrier is a structure that bars passage.

As a verb challenge

is to invite someone to take part in a competition.

As nouns the difference between roadblock and barrier

is that roadblock is something that blocks or obstructs a road while barrier is a structure that bars passage.

As a verb roadblock

is (colloquial) to prevent, hinder.

As nouns the difference between barrier and hinderance

is that barrier is a structure that bars passage while hinderance is .

As nouns the difference between barrier and problem

is that barrier is a structure that bars passage while problem is a difficulty that has to be resolved or dealt with.

As an adjective problem is

difficult to train or guide; unruly.

As a noun barrier

is a structure that bars passage.

As an adjective fort is

.

As a verb fort is

.

Barrier is a related term of precinct.

As nouns the difference between barrier and precinct

is that barrier is a structure that bars passage while precinct is (chiefly|in the plural) an enclosed space having defined limits, normally marked by walls.

As nouns the difference between line and barrier

is that line is a path through two or more points (compare ‘segment’); a continuous mark, including as made by a pen; any path, curved or straight while barrier is a structure that bars passage.

As a verb line

is to place (objects) into a line (usually used with "up"); to form into a line; to align.

Barrier is a related term of confines.

As a noun barrier

is a structure that bars passage.

As a verb confines is

.

As nouns the difference between barrier and difficulty

is that barrier is a structure that bars passage while difficulty is the state of being difficult, or hard to do.

As nouns the difference between trouble and barrier

is that trouble is a distressful or dangerous situation while barrier is a structure that bars passage.

As a verb trouble

is to disturb, stir up, agitate (a medium, especially water).