noun. Something that stands in the way of or holds up progress.

noun. That which opposes or stands in the way; something that obstructs progress; a hindrance or obstruction.

noun. Objection; opposition.

noun. Synonyms Difficulty, Obstacle, Obstruction, Impediment, check, barrier. A difficulty embarrasses, an obstacle stops us. We remove [or overcome] the one, we surmount the other. Generally the first expresses something arising from the nature and circumstances of the affair; the second something arising from a foreign cause. An obstruction blocks the passage, and is generally put in the way intentionally. An impediment literally clogs the feet and so may continue with one, hindering his progress, while a difficulty once overcome, an obstacle once surmounted, or an obstruction once broken down, leaves one free to go forward without hindrance.

Obstinate; stubborn.

noun. That which stands in the way, or opposes; anything that hinders progress; a hindrance; an obstruction, physical or moral.

noun. Something that impedes, stands in the way of, or holds up progress

noun. something immaterial that stands in the way and must be circumvented or surmounted

noun. an obstruction that stands in the way (and must be removed or surmounted or circumvented)

"a tear in my eye for the lonely man who knew well that the only obstacle to his success was the _one_ that people never _could_ see, and that the _obstacle himself_ was never _likely_ to see."

obstacle-race  

barrier  burden  challenge  complication  constraint  

apex  baffle  bar  barrage  barrier