preoccupy vs preoccupancy

preoccupy is not a noun while preoccupancy is a noun.

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

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

preoccupy (verb)	preoccupancy (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