quick and energetic; "a brisk walk in the park"; "a lively gait"; "a merry chase"; "traveling at a rattling rate"; "a snappy pace"; "a spanking breeze"
an obstruction that stands in the way (and must be removed or surmounted or circumvented)
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"