bottleneck

1. The narrow portion that forms the pouring spout of a bottle; the neck of a bottle.
2. A portion of a bottleneck placed on the finger and used as a guitar slide.
3. In traffic, any narrowing of the road, especially resulting in a delay. (figuratively)
4. The part of a process that is too slow or cumbersome due to the lessening of available throughput. (figuratively) · It is easy to create entries; processing the paperwork is the bottleneck.· The bottleneck in this computer program is the inefficient sorting process; we should replace it with a faster one.

Plural bottlenecks