smallholding vs acres

smallholding and acres both are nouns.

Word	Noun	Adjective	Verb	Adverb
smallholding	Yes	No	No	No
acres	Yes	No	No	No

As nouns, acres is a hypernym of smallholding; that is, acres is a word with a broader meaning than smallholding:

smallholding: a piece of land under 50 acres that is sold or let to someone for cultivation
acres: extensive landed property (especially in the country) retained by the owner for his own use

Other hypernyms of smallholding include demesne, estate, land, landed estate.

smallholding (noun)	acres (noun)
a piece of land under 50 acres that is sold or let to someone for cultivation	extensive landed property (especially in the country) retained by the owner for his own use