If you can’t find a definition of a term in BLACKS, you can search in Rise of American Law – Dictionaries and Words and Phrases (ROAL-DICT) to scan a number of older dictionaries at once.

You can find definitions of terms from old English law, Roman law, Indian/Hindu law, etc. For example TRINIUMGELDUM does not appear in BLACKS, but there are 3 entries for it in ROAL-DICT.