Aard 2 is a lightweight, high-performance offline dictionary reader. It uses the "Slob" format.
Download the Kiwix reader, then use its internal library manager to search for "Wiktionary" in your preferred language.
Having a local copy of Wiktionary offers several distinct advantages over the browser-based version:
You will need to find a pre-formatted Wiktionary database (often in StarDict format) and point the software to that folder.
Kiwix is the gold standard for offline Wikipedia and Wiktionary access. It uses highly compressed ZIM files to store entire websites.