n.

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

   在解決問題之前，我們必須克服一些瓶頸。

2. 障礙物；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.