There are multiple definitions - click on the translation that matches your context.

Ersitzung

Substantiv

partial

adverse possession

noun

Comparative law notes

Austria

This would be the appropriate term in situations where ownership rights in land are being acquired through adverse possession over the required term.

Definitions of adverse possession

English

a way of gaining title to real property from another by retaining possession for a period of time established by law and complying with certain conditions

He acquired the property through adverse possession.