preoccupancy vs preoccupy

preoccupancy is a noun but preoccupy is not a noun.

Word	Noun	Adjective	Verb	Adverb
preoccupancy	Yes	No	No	No
preoccupy	No	No	Yes	No

preoccupancy (noun)	preoccupy (noun)
the act of taking occupancy before someone else does
the mental state of being preoccupied by something

preoccupancy (verb)	preoccupy (verb)
	engage or engross the interest or attention of beforehand or occupy urgently or obsessively
	occupy or take possession of beforehand or before another or appropriate for use in advance