bottleneck

As a noun bottleneck

is the narrow portion that forms the pouring spout of a bottle; the neck of a bottle.

As a verb bottleneck

is to slow by causing a bottleneck.

As an adjective stagnant is

lacking freshness, motion, flow, progress, or change; stale; motionless; still.

As nouns the difference between bottleneck and impediment

is that bottleneck is the narrow portion that forms the pouring spout of a bottle; the neck of a bottle while impediment is a hindrance; that which impedes or hinders progress.

As a verb bottleneck

is to slow by causing a bottleneck.

As nouns the difference between taxonomy and bottleneck

is that taxonomy is the science or the technique used to make a classification while bottleneck is the narrow portion that forms the pouring spout of a bottle; the neck of a bottle.

As a verb bottleneck is

to slow by causing a bottleneck.