Drop-off (noun)

1. A steep or sudden decline in something.
2. A place where something or someone is left, typically by being abandoned or discarded.
3. A point or place where a road, path, or track becomes steep and descends abruptly.

Origin:

Late 19th century: from drop off, verbal phrase from the verb drop.

Examples:

1. There was a sharp drop-off in sales last month.
2. The drop-off point for the hike was at the ranger station.
3. The road had a dangerous drop-off on one side.