1. (

• obstacle ,
• obstruction

) something immaterial that stands in the way and must be circumvented or surmounted; "lack of imagination is an obstacle to one's advancement"; "the poverty of a district is an obstacle to good education"; "the filibuster was a major obstruction to the success of their plan" ;

2. (

• obstacle

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