OpenThesaurus Deutsch Dictionary plugin

The plug‑in adds a German thesaurus to macOS’s built‑in Dictionary app, allowing users to look up synonyms directly within the system dictionary. It searches for all synonym forms, not only the headword, and can match parts of phrases or hyphenated compounds, extending beyond the default prefix‑only lookup. The full database, derived from the online OpenThesaurus project, is bundled with the plug‑in, so searches work offline.

With roughly 176 000 entries, the thesaurus provides extensive coverage for German vocabulary. Installation can be performed by double‑clicking the provided DMG, copying the .dictionary folder into the appropriate Library/Dictionaries directory, or using Homebrew for a command‑line setup. The plug‑in integrates into Dictionary’s preferences, where it can be enabled or disabled per user.

Targeted at macOS users who need German synonym lookup while writing or researching, the tool offers a native, offline alternative to web‑based thesauri, adhering to the stability expectations of a mature, core macOS productivity extension.