drop-off

nouns

a noticeable deterioration in performance or quality
"the team went into a slump"; "a gradual slack in output"; "a drop-off in attendance"; "a falloff in quality"
drop-off, falling off, falloff, slack, slump
is derived from
drop off
a steep high face of rock
"he stood on a high cliff overlooking the town"; "a steep drop"
cliff, drop, drop-off
a change downward
"there was a decrease in his temperature as the fever subsided"; "there was a sharp drop-off in sales"
decrease, drop-off, lessening
is derived from
drop off