n.

1. 瓶颈
   Several bottlenecks need to be overcome before we can solve our problem.

   在解决问题之前，我们必须克服一些瓶颈。

2. 障碍物；隘路

n.

1. a narrow section of road where traffic flow is restricted.
2. a device worn on a guitarist's finger and used to produce sliding effects on the strings.