fall off

phr.v. to become detached and drop from a higher place or surface.

phr.v. to become detached from a surface or to drop from a position of support. Intransitive or transitive depending on whether the surface is mentioned.

“Be careful not to let your phone fall off the edge of the table.”

“The old tiles began to fall off the roof after the severe storm, creating a hazard for anyone walking near the building.”

phr.v. to become less in amount, number, or quality.

phr.v. to diminish in quantity, intensity, or quality. Intransitive in this sense.

“Attendance at the club started to fall off during the winter months.”

“The quality of the manufacturer's output has fallen off significantly since they switched to cheaper raw materials last year.”

phr.v. to change the direction of a boat to move more with the wind.

phr.v. to steer a vessel further away from the direction of the wind. Intransitive usage.

“The captain told the crew to fall off to catch the breeze.”

“As the gust hit, the helmsman had to fall off quickly to prevent the boat from heeling over too far.”

Technical

n. a decrease in the amount or number of something.

n. a reduction or decline in quantity, quality, or activity. Often written as one word 'falloff'.

“There has been a sharp fall off in sales since the new tax was introduced.”

“Economists are concerned about the sudden fall off in consumer spending, which could signal a broader market slowdown.”