Noah Webster
Obstacle
OB'STACLE, noun [Latin obsto, to withstand; ob and sto.]
That which opposes; any thing that stands in the way and hinders progress; hinderance; obstruction, either in a physical or moral sense. An army may meet with obstacles on its march; bad roads are obstacles to traveling; prejudice is an obstacle to improvement; want of union is often an insuperable obstacle to beneficial measures.