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

Anfechtung

Substantiv

partial

will contest

Comparative law notes

Switzerland

In estate law matters, the Anfechtung closely resembles the action taken by someone "contesting the will", which is a formal objection raised against the validity of a will based on the contention that the will does not reflect the actual intent of the testator (the party who made the will) or that the will is otherwise invalid. Will contests generally focus on the assertion that the testator lacked testamentary capacity or was subject to improper influence or fraud. A will can be contested in its entirety or in part.