名詞 bottle neck:

1. a narrowing that reduces the flow through a channel
   同義詞：constriction, bottleneck, chokepoint
2. the narrow part of a bottle near the top
   同義詞：bottleneck

動詞 bottle neck:

1. slow down or impede by creating an obstruction
   同義詞：bottleneck
2. become narrow, like a bottleneck
   同義詞：bottleneck