a narrowing that reduces the flow through a channel
"The construction of the new dam created a severe bottleneck in the river, drastically reducing the flow downstream during the rainy season."
the narrow part of a bottle near the top
"The old glass had a tiny bottleneck that made it impossible to pour out all the liquid at once."
The narrow portion that forms the pouring spout of a bottle; the neck of a bottle.
"The heavy glass bottleneck was so fragile that I had to hold it carefully while trying to pour out the last drop of wine."
slow down or impede by creating an obstruction
"His laziness has bottlenecked our efforts to reform the system"
To slow by causing a bottleneck.
"The new security checks will bottleneck traffic at the border, causing long delays for everyone trying to leave the country."