expanse vs acreage

expanse and acreage both are nouns.

Word	Noun	Adjective	Verb	Adverb
expanse	Yes	No	No	No
acreage	Yes	No	No	No

As nouns, acreage is a hyponym of expanse; that is, acreage is a word with a more specific, narrower meaning than expanse:

expanse: the extent of a 2-dimensional surface enclosed within a boundary
acreage: an area of ground used for some particular purpose (such as building or farming)

Other hyponyms of expanse include land area, footprint, erasure, blank space, place, space, space, balk, baulk, plane section, section.

expanse (noun)	acreage (noun)
the extent of a 2-dimensional surface enclosed within a boundary	an area of ground used for some particular purpose (such as building or farming)
a wide scope
a wide and open space or area as of surface or land or sky