Medida cautelar / Medidas cautelares
The Spanish legal terms medida cautelar and medidas cautelares are notoriously tricky to render into English as there is no single, system-neutral equivalent.
Súmula vinculante
Untranslatables
Uchastniki v. aktsionery
The distinction between types of corporate ownership in Russian law requires English readers to overcome what would seem an odd turn of phrase.
Trânsito em julgado

Trânsito em julgado does not have a single, universally adopted English equivalent, but several translations are commonly used depending on the context.
Usucapio
Usucapio is a concept from Roman law by which a title or right to property is acquired through uninterrupted and undisputed possession for a prescribed term.
Verein
The legal figure of Verein is widely used in Switzerland, Germany, Austria and Liechtenstein…
Amparo

The Spanish-language legal figure of amparo is usually left untranslated, due to its specificity. Might “constitutional challenge” be a good translation?
Dolo

The translation of the Portuguese legal term dolo into English is notoriously complex, as dolo is used in both civil and criminal law, and the scope of the term does not fully overlap with the meanings of the common-law terms which it is usually translated as.
Aval
The Portuguese noun aval poses particular challenges to a legal translator, which revolve on its wide, context-dependent semantic drift: in financial documents, it normally means “surety” or “guarantee” (e.g. Nenhum aval é necessário para este financiamento, “no guarantee is required for this loan”)
Visto
Visto is another legal Portuguese term that makes translators break out in a cold sweat.