recede vs drop off

recede and drop off both are verbs.

Word	Noun	Adjective	Verb	Adverb
recede	No	No	Yes	No
drop off	No	No	Yes	No

As verbs, recede and drop off are synonyms defined as:

Other synonyms of recede include fall back, fall behind.

recede (verb)	drop off (verb)
become faint or more distant	change from a waking to a sleeping state
retreat	fall to a lower standard
pull back or move away or backward	fall or diminish
	retreat
	remove (cargo, people, etc.) from and leave